Question

factorise: 12(a + b)² - (a+ b) - 35 

Answer 1

12(a + b)² - (a+ b) - 35 

= 12 (a + b)² - 21 (a + b) + 20 (a + b) - 7

= 3(a + b) [4 (a + b) - 7] + 5[4 (a + b) - 7]

= (4a + 4b - 7)(3a + 3b + 5)