Algebraic Identities Year 8

Identity 1

100

(2b+3)²

4b²+12b+9

200

(9e-2f)²

81e²-36ef+4f²

300

904²

81721

400

791²

625681

500

4a²+32a+64

4(a+4)²

Identity 2

100

(9e-2f)²

81e²-36ef+4f²

200

(3a-1/4b)²

9a²-3/2ab+1/16b²

300

3a²-36a+108

3(a-6)²

400

201²-402+1

40000

500

Given that x²+y² =43 and 4xy =48 find the value of (2x-2y)²

76

Identity 3

100

(9+4c)(9-4c)

81-16c²

200

(1/2a+b)(1/2a-b)

1/4a²-b²

300

81ef²-4eg²

e(9f+2g)(9f-2g)

400

(e-3)²-16f²

(e-3+4f)(e-3-4f)

500

Given that x^2-y²=6 and x-y=2, find the value of (x+y)²

9

Chapter 3

100

Factorise (2a+b)(x+y) + (a+b)(x+y)

(3a+2b)(x+y)

200

6a²+31a+5

(6a+1)(a+5)

300

Expand (4c+5d)(5c+7d)

20c²+53cd+35d²

400

Expand and simplify (2x-3)²-3x(x+7)

x²-33x+9

500

Factorise the expression 18x²-102x+60. The length of a rectangle is (3x-2)cm and its area is (18x² -102x+60). Find an expression in terms of x, for the breath of the rectangle. 

6(3x-2)(x-5) so breath (6x-30)cm