Q9 of 137 Page 100

Factories:

20a2 – 45b2

We have,


20a2 – 45b2


= 5(4a2 – 9b2)


By using the formula a2 – b2 = (a + b)(a – b)


We get,


20a2 – 45b2 = 5(4a2 – 9b2)


= 5{(2a)2 – (3b)2}


= 5(2a + 3b)(2a – 3b)


More from this chapter

All 137 →
7

Factories:

16a2 – 144

 8

Factories:

63a2 – 112b2

 10

Factories:

12x2 – 27

 11

Factories:

x3 – 64x