Answer: 
Step-by-step explanation:
You need to use the following formula that is used to find the area of a trapezoid:

Where "M"and "m" are the bases of the trapezoid and "h" is the height of the trapezoid.
Based on the information given in the exercise, you can identify that:

Knowing these values, you can substitute them into the formula:

Finally, you must evaluate in order to find its area. This is:

20 times 4 will get to 80
Answer:
39/10
3 9/10
3.9
Step-by-step explanation:
Convert the mixed number to an improper fraction
Step-by-step explanation:
y=2(x+3)² y=x²
x²=2(x²+9+6x)
x²=2x²+18+12x
0=x²+18+12x
x²+18+12x=0