Examples with solutions for Square of sum: Using short multiplication formulas

Exercise #1

Given the rectangle ABCD

AB=X

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

We mark the length of the diagonal A the rectangle in m

Check the correct argument:

XXXmmmAAABBBCCCDDD

Video Solution

Step-by-Step Solution

Given that:

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

Given that AB equals X

We will substitute accordingly in the formula:

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 focus on triangle ABC and use the Pythagorean theorem:

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

Let's substitute the 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

We'll 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 #2

Find X

(3x+1)2+8=12 (3x+1)^2+8=12

Video Solution

Answer

x1=13,x2=1 x_1=\frac{1}{3},x_2=-1

Exercise #3

Find X

7=5x2+8x+(x+4)2 7=5x^2+8x+(x+4)^2

Video Solution

Answer

43±106 -\frac{4}{3}\pm\frac{\sqrt{10}}{6}

Exercise #4

Solve the following equation:

(x+3)2+2x2=18 (x+3)^2+2x^2=18

Video Solution

Answer

x1=1,x2=3 x_1=1,x_2=-3

Exercise #5

(x+2)212=x2 (x+2)^2-12=x^2

Video Solution

Answer

x=2 x=2

Exercise #6

Calculate x according to the figure shown below below.

x>0

x+1x+1x+1xxxx+2x+2x+2

Video Solution

Answer

x=3 x=3

Exercise #7

(x+1)2=x2 (x+1)^2=x^2

Video Solution

Answer

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

Exercise #8

Find X

7x+1+(2x+3)2=(4x+2)2 7x+1+(2x+3)^2=(4x+2)^2

Video Solution

Answer

1±338 \frac{1\pm\sqrt{33}}{8}

Exercise #9

Solve the equation

2x22x=(x+1)2 2x^2-2x=(x+1)^2

Video Solution

Answer

Answers a + b

Exercise #10

Solve the following equation:

(x+1)2=(2x+1)2 (-x+1)^2=(2x+1)^2

Video Solution

Answer

x1=0,x2=2 x_1=0,x_2=-2

Exercise #11

(1x+12)2(1x+13)2=8164 \frac{(\frac{1}{x}+\frac{1}{2})^2}{(\frac{1}{x}+\frac{1}{3})^2}=\frac{81}{64}

Find X

Video Solution

Answer

x=1,177 x=1,-\frac{17}{7}

Exercise #12

Solve the following equation:

(x+3)2=2x+5 (x+3)^2=2x+5

Video Solution

Answer

x=2 x=-2

Exercise #13

Write an algebraic expression for the area of the square below.

x+1x+1x+1

Video Solution

Answer

x2+2x+1 x^2+2x+1

Exercise #14

Solve the following equation:

1(x+1)2+1x+1=1 \frac{1}{(x+1)^2}+\frac{1}{x+1}=1

Video Solution

Answer

12[1±5] -\frac{1}{2}[1\pm\sqrt{5}\rbrack

Exercise #15

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 #16

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

Video Solution

Answer

x=0 x=0

Exercise #17

The square below has an area of 36.

x>0

Calculate x.

363636x+1x+1x+1

Video Solution

Answer

x=5 x=5

Exercise #18

Solve the following equation:

x3+1(x+1)2=x \frac{x^3+1}{(x+1)^2}=x

Video Solution

Answer

x=12 x=\frac{1}{2}

Exercise #19

Shown below is the rectangle ABCD.

AB = y

AD = x

Express the square of the sum of the sides of the rectangle using the area of the triangle DEC.

YYYXXXAAABBBCCCDDDEEE

Video Solution

Answer

(x+y)2=4s[sy2+sx2+1] (x+y)^2=4s\lbrack\frac{s}{y^2}+\frac{s}{x^2}+1\rbrack