Question

Simplify the expressions and find the value:

a) x (x-3) + 2 for x = 2, -1
b)3y (2y - 7) - 3 (y-4) - 63 for y = 1, y = 0

Answer 1

`x(x−3)+2=x.x−3x+2 \\ =x2−3x+2 \\F or x=1 \\ putting \:  x=1  \: in \: expression \\ x2−3x+2=(1)2−3(1)+2 \\ =1−3+2 \\ =3−3 \\ =0`

`Solve  \: 3y(2y−7)−3(y−4)−63 for y=−2 \\ First \: simplify \: it, \\ =6y2−21y−3y+12−63 \\ =6y2−24y−51 \\ Put \:  y=−2 \: =6(−2)2−24(−2)−51 \\ =6×4+48−51 \: 6×4+48−51 \\ 24+48−51 \\ =21`