Examples with solutions for Square of sum: Using multiple rules

Exercise #1

Solve the following equation:

(x+3)2=(x3)2 (x+3)^2=(x-3)^2

Video Solution

Step-by-Step Solution

Let's examine the given equation:

(x+3)2=(x3)2 (x+3)^2=(x-3)^2 First, let's simplify the equation, for this we'll use the perfect square formula for a binomial squared:

(a±b)2=a2±2ab+b2 (a\pm b)^2=a^2\pm2ab+b^2 ,

We'll start by opening the parentheses on both sides simultaneously using the perfect square formula mentioned, then we'll move terms and combine like terms, and in the final step we'll solve the resulting simplified equation:

(x+3)2=(x3)2x2+2x3+32=x22x3+32x2+6x+9=x26x+9x2+6x+9x2+6x9=012x=0/:12x=0 (x+3)^2=(x-3)^2 \\ \downarrow\\ x^2+2\cdot x\cdot3+3^2= x^2-2\cdot x\cdot3+3^2 \\ x^2+6x+9= x^2-6x+9 \\ x^2+6x+9- x^2+6x-9 =0\\ 12x=0\hspace{6pt}\text{/}:12\\ \boxed{x=0} Therefore, the correct answer is answer A.

Answer

x=0 x=0

Exercise #2

The rectangle ABCD is shown below.

AB = X

The ratio between AB and BC is x2 \sqrt{\frac{x}{2}} .


The length of diagonal AC is labelled m.

XXXmmmAAABBBCCCDDD

Determine the value of m:

Video Solution

Step-by-Step Solution

We know that:

ABBC=x2 \frac{AB}{BC}=\sqrt{\frac{x}{2}}

We also know that AB equals X.

First, we will substitute the given data into the formula accordingly:

xBC=x2 \frac{x}{BC}=\frac{\sqrt{x}}{\sqrt{2}}

x2=BCx x\sqrt{2}=BC\sqrt{x}

x2x=BC \frac{x\sqrt{2}}{\sqrt{x}}=BC

x×x×2x=BC \frac{\sqrt{x}\times\sqrt{x}\times\sqrt{2}}{\sqrt{x}}=BC

x×2=BC \sqrt{x}\times\sqrt{2}=BC

Now let's look at triangle ABC and use the Pythagorean theorem:

AB2+BC2=AC2 AB^2+BC^2=AC^2

We substitute in our known values:

x2+(x×2)2=m2 x^2+(\sqrt{x}\times\sqrt{2})^2=m^2

x2+x×2=m2 x^2+x\times2=m^2

Finally, we will add 1 to both sides:

x2+2x+1=m2+1 x^2+2x+1=m^2+1

(x+1)2=m2+1 (x+1)^2=m^2+1

Answer

m2+1=(x+1)2 m^2+1=(x+1)^2

Exercise #3

(x+y)2(xy)2+(xy)(x+y)=? (x+y)^2-(x-y)^2+(x-y)(x+y)=\text{?}

Video Solution

Answer

x2+4xyy2 x^2+4xy-y^2

Exercise #4

(x+3)2+(x3)2=? (x+3)^2+(x-3)^2=\text{?}

Video Solution

Answer

2x2+18 2x^2+18

Exercise #5

Find a,b a ,b such that:

(a+b)(ab)=(a+b)2 (a+b)(a-b)=(a+b)^2

Video Solution

Answer

a=b a=-b o

0=b 0=b

Exercise #6

(a+3b)2(3ba)2=? (a+3b)^2-(3b-a)^2=\text{?}

Video Solution

Answer

12ab 12ab

Exercise #7

Given a circle whose center O. From the center of the circle go out 2 radii that cut the circle at the points A and B.

Given AO⊥OB.

The side AB is equal to and+2.

Express band and the area of the circle.

and+2and+2and+2AAABBBOOO

Video Solution

Answer

π2[y2+4y+4] \frac{\pi}{2}[y^2+4y+4]

Exercise #8

Find a X given the following equation:

(x+3)2+(2x3)2=5x(x35) (x+3)^2+(2x-3)^2=5x(x-\frac{3}{5})

Video Solution

Answer

6 6