2] Let the other side of the rectangle be y, so the area is:

xy, which is 77 so,

xy = 77, so

y = 77/x

The perimeter, P = 2x + 2y, so substitute y = 77/x, and you get

P = 2x + 2*77/x, so,

P = 2x + 154/x

3] I`m assuming that x is the side of the base. Let y be the

height of the box.

V = 9 = x^2y, so,

y = 9/x^2

Total surface area of the box = area of base add area of the

four sides, so,

S = x^2 + 4xy, so substitute y = 9/x^2, and you get:

S = x^2 + 4x*9/x^2,so,

S = x^2 + 36/x

Hope this helps, Twiggy.

if you need to know how i got that…

M=(y1)-(y2) / (x1)-(x2)

M=(-3a+2) – (-3(a-4h)+2) / (a) – (a+h)

M=(-3a+2 + 3a+4h+2) / (a) – (a+h)

M=(2 + 4h+2) / (h)

M=(4h+2) / (h)

M=(4+2) / 1

M=6/1