x+3x+3x=21
7x=21
x=3
3, 9, 9=21
the answers are 3, 9, and 9
2y-4=3y-5
-4=y-5
1=y
Answer: y=1
1.
Parallelogram with base a = 20 in. and height h = 16 in.
Triangle with base a = 20 in. and height b = 8 in.
so:

2.
Trapezoid with base b₁ = 14 cm, base b₂ = 4 cm and height h = 10 cm
Triangle with base b₁ = 14 cm and height x = 18 cm - 10 cm = 8 cm
so:

3.
We have three rectangles:

4.
Area of a circle:

Area of a rectangle:

Area of the shaded region: