Question

Factorise the following: i) 42- x -x^2 ii) 16x^2 + 25- 40x

Answer 1

Answer:

-(x+6)(x+7)

(4x-5)(4x-5)

Step-by-step explanation:

Answer 2

Answer:

$(-x+6)(x+7)$

$(4x-5)(4x-5)$

Step-by-step explanation:

$-x^2-x+42$

$-\left(x^2+x-42\right)$

$-\left(x-6\right)\left(x+7\right)$

$(-x+6)(x+7)$

$16x^2 + 25- 40x$

$16x^2-40x+25$

$\left(4x\right)^2-2\cdot \:4x\cdot \:5+5^2$

$\left(4x-5\right)^2$

$(4x-5)(4x-5)$