Mathematics
Factorise the following:
x(12x + 7) - 10
Factorisation
30 Likes
Answer
x(12x + 7) - 10 = 12x2 + 7x - 10.
To factorise 12x2 + 7x - 10, we want to find two real numbers whose sum is 7 and product is 12 × (-10) = -120. By trial, we see that 15 + (-8) = 7 and 15 × (-8) = -120.
∴ 12x2 + 7x - 10 = 12x2 + 15x + (-8x) - 10
= 12x2 + 15x - 8x - 10
= 3x(4x + 5) - 2(4x + 5)
= (4x + 5)(3x - 2).
Hence, x(12x + 7) - 10 = (4x + 5)(3x - 2).
Answered By
17 Likes