Free Printable identities-8th

1.

Find the product of (2x - 3y)(2x + 5y) using suitable identity.

a)

x²+ 4xy - 15xy

b)

2x²+ 4xy - 15xy

c)

x²- 15xy - 15xy

d)

2x²- 6xy - 15xy

2.

Expand (4x − 5)(4x + 5).

a)

4x² − 25

b)

4x² + 25

c)

16x² + 25

d)

16x² − 25

3.

(x² - y²) × (x² + y²) = ______

a)

2x² + 2y²

b)

x⁴ - y⁴

c)

x⁴ + y⁴

d)

2x⁴

4.

The square of x² - 2y²is ______

a)

x⁴ - 4x²y²+ 4y⁴

b)

x⁴ + 4x²y²+ 4y⁴

c)

x⁴ - 4x²y²- 4y⁴

d)

None of the above

5.

Expand (4x − 5)(4x + 5).

a)

4x² − 25

b)

4x² + 25

c)

16x² + 25

d)

16x² − 25

6.

(x² - y²) × (x² + y²) = ______

a)

2x² + 2y²

b)

x⁴ - y⁴

c)

x⁴ + y⁴

d)

2x⁴

7.

$Expansion\ of\ \left(x\ +4\right)^2\ is\$

a)

$x^2+8x+16$

b)

x $x^2+8x+4$

c)

$x^2-8x+16$

d)

$x^2+8x-16$

8.

$\left(4a+2b\right)^2=$

a)

$16a^2+8ab-4b^2$

b)

$16a^2-8ab-4b^2$

c)

$16a^2-8ab+4b^2$

d)

$16a^2+8ab+4b^2$

9.

$25a^2-4b^2$ is of the form

a)

$a^2-b^2$

b)

$\left(a+b\right)^2$

c)

$\left(a-b\right)^2$

d)

none of these

10.

(5-p)(5-p) is of the form

a)

$\left(a-b\right)\left(a+b\right)$

b)

$\left(a-b\right)^2$

c)

$\left(a+b\right)^2$

d)

none of these

11.

$\left(a-5\right)\left(2a-9\right)$ is of the form

a)

$\left(a+b\right)\left(a-b\right)$

b)

$\left(a+b\right)^2$

c)

$\left(x+a\right)\left(x+b\right)$

d)

none of these

12.

Expand (x−4)².

a)

x² −8x+16

b)

x² −8x−16

c)

x² +8x+16

d)

x² −16

13.

Expand (2x + 1)².

a)

4x² +4x +1

b)

4x² +1

c)

4x² +2x +1

d)

4x² +4x +2

14.

If a+b=7, ab = 10, find a² + b²

a)

28

b)

29

c)

30

d)

27

15.

Use identity to find , (x-6)(x-19)

a)

x² - 25x +114

b)

x² - 25x -114

c)

x² + 25x +114

d)

x² + 25x -114

16.

$If\ x^2\ +\ \frac{1}{x^2}\ =\ 18,\ find\ x\ -\ \frac{1}{x}$

a)

4

b)

-4

c)

$+-4$

d)

16

17.

If area of the triangle is 24 ( x²yz + xy²z + xyz²) and its length is 8xyz, then its breadth is ?

a)

3(x + y + z)

b)

3xyz

c)

3(x + y - z)

d)

none

18.

Using identity find 201 x 199

a)

3000

b)

3999

c)

39999

d)

31111

19.

Find 87² - 13²

a)

7200

b)

7300

c)

7400

d)

7500

20.

(a + b)² - (a - b)²=

a)

4ab

b)

2 (a² + b²)

c)

a² – b²

d)

(a - b ) (a² + ab + b²)

21.

2 (a² + b²) =

a)

(a + b)²

b)

a² – b²

c)

(a + b)² + (a - b)²

d)

(a + b)² - (a - b)²

identities-8th

Total questions: 21

Worksheet time: 26mins

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