Answer:
a = 7
Step-by-step explanation:
3(1 - 2a) = -3a - 18
3 - 6a = - 3a - 18
Add 18 to each side:
3 + 18 - 6a = - 3a - 18 + 18
21 - 6a = - 3a
Add 6a to each side:
21 - 6a + 6a = - 3a + 6a
21 = 3a
3a = 21
Divide each side by 3:
3a ÷ 3 = 21 ÷ 3
a = 7
When estimating, compatible numbers are numbers that are close in value to the actual numbers, and which make it easy to do mental arithmetic.
The answer to your question is = 148.06
Answer:
B
Step-by-step explanation:
3 rectangles are 3 x 7 x 2 = 42
2 triangles are 2 x 1/2 x 2 x 
= 2
note that you have to use Pythagoras Theorem to solve for the height of the triangle
