中二簡單數學~~~~

Prove (2x - 1)(x - 2) = x(2x - 4) - (x - 2) is an identity

L.H.S.

= (2x - 1)(x - 2)

= 2x(x - 2) - (x - 2)

= x[2(x - 2)] - (x - 2)

= x(2x - 2 X 2) - (x - 2)

= x(2x - 4) - (x - 2)

= R.H.S.

Hence, we proved the identity.

(2x-1)(x-2)=x(2x-4)-(x-2)

(2x-1)(x-2)=2x2 -4x-(x-2)

2x2-4x-x+2=2x2-4x-x+2

2x2-2x2-4x-x+4x+x=2-2

x=0

.
. .The value of x is 0

2x(2次方)+2=2x(2次方)-4x-x+2
4x+x-2=-2
x=0