Question

Please help!!
Evaluate:

1. 5x(x-2)-2x^2 for x=-2

2. 2x^2-5x+8 for x=3

Answer 1

1. 32.

2. 11.

Explanation:

1. 5x(x-2)-2x^2 for x=-2:

= 5(-2)( -2-2)-2(-2)^2

= -10*-4 - 2*4

= 40-8

= 32.

2. 2x^2-5x+8 for x=3:

= 2(3)^2 -5(3)+8

= 18 - 15 + 8

= 11.

Answer 2

Explanation:

1) 5x(x-2)-2x^2 for x =2

= 5(-2)(-2-2) -2(2)^2

= -10(-4) -2(4)

= 40 - 8

= 36

2) 2x^2 - 5 + 8 for x = 3

= 2(3)^2 - 5(3) + 8

= 2(9) - 15 + 8

= 18 - 15 + 8

= 3 + 8

= 11