Question

100 points!! Brainliest if correct

Answer 1

Answer:

SA = 16x^2 +30x+6

Step-by-step explanation:

The surface area is given by

SA = 2 (lw + lh + wh)

The length is 2x, the width is (x+3) and the height is (2x+1)

SA = 2 ((2x)*(x+3) + (2x)*(2x+1) + (x+3) (2x+1))

We need to distribute

SA = 2 ((2x^2+6x) + (4x^2+2x) + (2x^2 +6x+x+3))

Combine like terms

SA = 2 (2x^2+ 4x^2+2x^2+6x+2x  +6x+x+3)

SA = 2 (8x^2+15x+3)

Multiply by 2

SA = 16x^2 +30x+6

Answer 2

Answer:

Step-by-step explanation:

Surface area = sum of all six faces

=2(2x)(x+3) + 2(2x)(2x+1) + 2(x+3)(2x+1)

=4x^2+12x + 8x^2+4x + 4x^2+14x+6

=16x^2 + 30x + 6