Which expression is equal to 6.5(2r – s) + 3.7r – 1.25s written in simplest form? A) 16.7r-7.75s
B) 16.7r-5.25s
C) 13r-6.5s+2.45
D) 13r-7.75s+2.45rs

A

Step-by-step explanation:

13r-6.5s+3.7r-1.25s

13r+3.7r-6.5s-1.25s

=16.7r-7.75s

Step-by-step explanation:

Surface area = lateral area + 2(area of base)

Lateral area = perimeter of base * height.

Because it is a isosceles right triangle, both sides are equal.

= 72

2 = 72. Divide both sides by 2

= 36.  Square both sides.

x = 6.

So the perimeter of the base = 6 + 6 + = 20.485281374239

Lateral area = 20.485281374239 * 7 = 143.397

Area of base is (1/2)base * height.

(1/2)(6)(6) = 18

Using the surface area formula

surface area = 143.397 + 2(18) = 179.4