Question

factorise (1) 6ab -b square +12ac-2bc (2) 9(2a-b) square -4(2a-b) -13​

Answer 1

Answer:

(1) 6ab -b²+12ac-2bc = b(6a-b) +2c(6a - b) = (6a-b)(b+2c)

(2) 9(2a-b)² - 4(2a-b) - 13

Let (2a-b) = x

Then, the expression = 9x² - 4x -13

Here, -13×9 = -117. Here, we have to find two numbers whose product is -117 and difference is 4. They are 13 and 9.

So, the expression = 9x² - (13-9)x - 13 = 9x²-13x +9x - 13

= x(9x-13)+1(9x-13) = (9x-13)(x+1) = [9(2a-b)-13] (2a-b+1) = (9a-9b-13)(2a-b+1)

Step-by-step explanation: