Answer:
I believe the answer is 7
(3x+4)+(5x2-1)+(2x+6)
remove unnecessary parenthesis
3x+4+(5x2-1)+(2x+6)
3x+4+(10-1)+2x+6
subtract the numbers
3x+4+9+2x+6
collect the like terms
5x+4+4+9+6
5x+19
Since the ratio is 3:4, and 12/4 is 3 than you do 3x3 and get 9 so the answer is 9:12 or 9 boys and 12 girls. To check your answer, you can do 3/4 (for 3:4) and that is 0.75. If you do that with 9:12 you also get 0.75.
1: (pi)5^2 = 78.54 then multiply that by 11 and you get 863.94
2: (pi)13^2= 530.93 then multiply that by 8 and you get 47247.44
3. (pi)18^2= 1017.88 then multiply that by 22 and you get 22393.36
Answer:

Step-by-step explanation:
We have:
(1) two trapezoids with bases b₁ = 7cm and b₂ = 5cm and the height h = 4cm
(2) three rectangles 3 cm × 7 cm, 3 cm × 4 cm and 3 cm × 5 cm.
The formula of an area of a trapezoid:

Substitute:

Calculate the areas of the rectangles:

The Surface Area:
