Solving Quadratic Equations using Factoring - Examples, Exercises and Solutions

We open the parentheses according to the formula:

$a(x+b)=ax+ab$

$5\times x+5\times3=0$

$5x+15=0$

We will move the 15 to the right section and keep the corresponding sign:

$5x=-15$

Divide both sections by 5

$\frac{5x}{5}=\frac{-15}{5}$

$x=-3$

To solve this equation, follow these steps:

• Step 1: Apply the distributive property to the equation:

  $2(4-x) = 2 \times 4 - 2 \times x = 8 - 2x$

• Step 2: Simplify the equation:

  The equation now becomes: $8 - 2x = 8$

• Step 3: Isolate the variable $x$ by simplifying the equation:

  First, subtract 8 from both sides:
  $8 - 2x - 8 = 8 - 8$
  This simplifies to:
  $-2x = 0$

• Step 4: Solve for $x$ by dividing both sides by -2:

  $x = \frac{0}{-2} = 0$

Therefore, the solution to the equation is $x = 0$.

To open parentheses we will use the formula:

$a(x+b)=ax+ab$

$(7\times-2x)+(7\times5)=77$

We multiply accordingly

$-14x+35=77$

We will move the 35 to the right section and change the sign accordingly:

$-14x=77-35$

We solve the subtraction exercise on the right side and we will obtain:

$-14x=42$

We divide both sections by -14

$\frac{-14x}{-14}=\frac{42}{-14}$

$x=-3$

To solve this problem, we'll follow these steps:

• Step 1: Apply the distributive property to the equation.
• Step 2: Combine like terms.
• Step 3: Solve for $x$.

Now, let's work through each step:

Step 1: Distribute the number 5 across the expression inside the parentheses:
$3x + 5(x + 4) = 0$ becomes $3x + 5x + 20 = 0$.

Step 2: Combine the like terms:
Combine $3x$ and $5x$ to get $8x$.
Thus, the equation becomes $8x + 20 = 0$.

Step 3: Solve for $x$:
Subtract 20 from both sides: $8x = -20$.
Finally, divide both sides by 8: $x = \frac{-20}{8}$.

Simplify the fraction: $x = -2.5$.

Therefore, the solution to the equation is $x = -2.5$.

To solve the linear equation $8a + 2(3a - 7) = 0$, we'll proceed with the following steps:

Step 1: Apply the Distributive Property.
The equation given is $8a + 2(3a - 7) = 0$.
First, distribute the 2 across the terms inside the parenthesis:
$2(3a - 7) = 2 \times 3a + 2 \times (-7) = 6a - 14$.
By substituting this back into the equation, we have:
$8a + 6a - 14 = 0$.

Step 2: Combine Like Terms.
Now, combine the terms containing $a$:
$8a + 6a = 14a$.
The equation now becomes:
$14a - 14 = 0$.

Step 3: Isolate the Variable.
Add 14 to both sides of the equation to isolate terms with $a$:
$14a - 14 + 14 = 0 + 14$, which simplifies to:
$14a = 14$.
Next, divide both sides by 14 to solve for $a$:
$a = \frac{14}{14} = 1$.

Therefore, the solution to the equation is $a = 1$.

Let's proceed to solve the linear equation $3(a+1) - 3 = 0$:

Step 1: Distribute the 3 in the expression $3(a+1)$.

We get:
$3 \cdot a + 3 \cdot 1 - 3 = 0$

This simplifies to:
$3a + 3 - 3 = 0$

Step 2: Simplify the expression by combining like terms.

We simplify this to:
$3a + 0 = 0$ or simply $3a = 0$

Step 3: Isolate $a$ by dividing both sides by 3.

$\frac{3a}{3} = \frac{0}{3}$

Thus,
$a = 0$

Therefore, the solution to the problem is $a = 0$.

The correct choice is the option corresponding to $a = 0$.

To solve the given linear equation $5 - (3b - 1) = 0$, follow these steps:

• Step 1: Simplify the equation.
  Start by distributing the negative sign through the parentheses:
  $5 - 3b + 1 = 0$
• Step 2: Combine like terms.
  Combine the constant terms on the left side:
  $6 - 3b = 0$
• Step 3: Isolate the variable $b$.
  Subtract 6 from both sides of the equation to isolate the term with $b$:
  $-3b = -6$
• Step 4: Solve for $b$.
  Divide both sides by -3 to solve for $b$:
  $b = \frac{-6}{-3} = 2$

Therefore, the solution to the equation is $b = 2$.

Let's first expand the parentheses using the formula:

$a(x+b)=ax+ab$

$(2\times x)+(2\times4)+8=0$

$2x+8+8=0$

Next, we will substitute in our terms accordingly:

$2x+16=0$

Then, we will move the 16 to the left-hand side, keeping the appropriate sign:

$2x=-16$

Finally, we divide both sides by 2:

$\frac{2x}{2}=-\frac{16}{2}$

$x=-8$

To solve the equation $-2(-4 + y) - y = 0$, we will follow these steps:

• Step 1: Distribute $-2$ inside the parenthesis.
• Step 2: Simplify and combine like terms.
• Step 3: Solve the equation for $y$.

Let's proceed with the solution:

Step 1: Distribute $-2$ in the expression $-2(-4 + y)$. This will transform the expression as follows:

$-2(-4 + y) = -2 \times -4 + (-2) \times y = 8 - 2y$.

After distributing, the equation becomes:

$8 - 2y - y = 0$.

Step 2: Combine like terms. Notice that $-2y - y$ is equivalent to $-3y$:

$8 - 3y = 0$.

Step 3: Solve for $y$. First, isolate the term with $y$ by subtracting 8 from both sides:

$-3y = -8$.

Next, divide both sides by $-3$ to find $y$:

$y = \frac{-8}{-3} = \frac{8}{3}$.

Thus, the solution for $y$ is $\frac{8}{3}$, which can be written as a mixed number:

$y = 2\frac{2}{3}$.

Therefore, the solution to the problem is $y = 2\frac{2}{3}$.

To solve for $x$ in the equation $\frac{1}{2}(x+3) = 0$, we will take the following steps:

• Step 1: Eliminate the fraction by multiplying both sides of the equation by 2.

• Step 2: Simplify the resulting equation to isolate the variable $x$.

Let's carry out these steps:
Step 1: Multiply both sides by 2:
$\Rightarrow 2 \times \frac{1}{2}(x + 3) = 2 \times 0$
$\Rightarrow x + 3 = 0$

Step 2: Solve the equation $x + 3 = 0$ for $x$:
Subtract 3 from both sides:
$\Rightarrow x = 0 - 3$
$\Rightarrow x = -3$

Therefore, the solution to the equation is $x = -3$.

We open the parentheses on the left side by the distributive property and use the formula:

$a(x+b)=ax+ab$

$-\frac{3}{2}x-12=\frac{1}{2}$

We multiply all terms by 2 to get rid of the fractions:

$-3x-12\times2=1$

$-3x-24=1$

We will move the minus 24 to the right section and keep the corresponding sign:

$-3x=24+1$

$-3x=25$

Divide both sections by minus 3:

$\frac{-3x}{-3}=\frac{25}{-3}$

$x=-\frac{25}{3}$

To solve this problem, we will follow these steps:

• Step 1: Multiply both sides of the equation by 4 to eliminate the fraction.
• Step 2: Simplify the resulting equation.
• Step 3: Solve for $x$.

Let's work through these steps:

Step 1: Start with the equation:

$\frac{1}{4}(x - 8) = 1$

Multiply both sides by 4 to remove the fraction:

$4 \times \frac{1}{4}(x - 8) = 4 \times 1$

This simplifies to:

$x - 8 = 4$

Step 2: To isolate $x$, add 8 to both sides of the equation:

$x - 8 + 8 = 4 + 8$

This results in:

$x = 12$

Therefore, the solution to the equation is $x = 12$.

To solve this problem, we will proceed with the following steps:

• Step 1: Start with the given equation: $-\frac{1}{4}(x-2)=3$.
• Step 2: Multiply both sides by -4 to eliminate the fraction: $(-4) \times -\frac{1}{4}(x-2) = (-4) \times 3$.
• Step 3: Simplify: $(x-2) = -12$.
• Step 4: Solve for $x$ by adding 2 to both sides: $x = -12 + 2$.
• Step 5: Simplify to find the value of $x$: $x = -10$.

Therefore, the solution to the equation is $x = -10$.

According to the multiple-choice options, the correct answer is choice 2: -10.

To solve the equation $-\frac{1}{2}(x+\frac{1}{4})=\frac{1}{8}$, we will first eliminate the fraction by multiplying both sides by the common denominator. The common denominator here is 8, so we proceed as follows:

• Step 1: Multiply both sides by 8 to eliminate the fractions:
  $8 \left(-\frac{1}{2}(x+\frac{1}{4})\right) = 8 \times \frac{1}{8}$
• Step 2: Simplify the left side:
  $-4(x+\frac{1}{4}) = 1$
• Step 3: Distribute $-4$ into the terms inside the parentheses:
  $-4x - 1 = 1$
• Step 4: Add 1 to both sides to isolate the term with $x$:
  $-4x = 2$
• Step 5: Divide both sides by $-4$ to solve for $x$:
  $x = \frac{2}{-4} = -\frac{1}{2}$

Therefore, the solution to the equation is $x = -\frac{1}{2}$.

Let's solve the given equation $\frac{1}{2}(x+3) - 8x = 3$.

First, distribute the $\frac{1}{2}$ inside the parentheses:
$\frac{1}{2}(x+3) = \frac{1}{2}x + \frac{1}{2} \times 3 = \frac{1}{2}x + \frac{3}{2}$.

Substitute back into the original equation:
$\frac{1}{2}x + \frac{3}{2} - 8x = 3$.

To eliminate the fraction, multiply every term by 2 to simplify:
$2 \times \left(\frac{1}{2}x + \frac{3}{2}\right) - 2 \times 8x = 2 \times 3$.

After clearing the fraction, the equation becomes:
$x + 3 - 16x = 6$.

Combine like terms involving $x$:
$x - 16x + 3 = 6$ simplifies to $-15x + 3 = 6$.

Isolate $x$ by subtracting 3 from both sides:
$-15x = 6 - 3$.
This simplifies to $-15x = 3$.

Finally, divide both sides by $-15$ to solve for $x$:
$x = \frac{3}{-15}$,
which simplifies to $x = -\frac{1}{5}$.

Therefore, the solution to the equation $\frac{1}{2}(x+3) - 8x = 3$ is $x = -\frac{1}{5}$.