Question

Solve the equations using factorisation method :
(I) x(x-5)=24
(ii) 2x²-(1/2)x=0

Answer 1

Simplifying x(x - 5) = 24
Reorder the terms: x(x- 5) = 24
=> ( x*x - 5*x ) = 24
=> x²- 5x = 24
=> x²- 5x - 24 = 0
Factorising:
Since b = -5 and c = -24
Factors of 24 = 1 x 24, 2 x 12, 3 x 8, or 4 x 6.
So we take -8 and 3 as they add up to give -5 and multiply to give -24

=> (x - 8)(x + 3) = 0
=> (x - 8) = 0 or (x + 3) = 0
=> x = 8 or x = -3

(ii)2x²-(1/2)x=0

Multiplying both sides by 2
=> 4x²- x = 0
=> x(4 - x) = 0
=> x = 0 or (4 - x) = 0
=> x = 0 or x = 4