I really need help with math homework. Please and thank you!

Question

R is the first quadrant region enclosed by the x-axis, the curve y = 2x + a, and the line x = a, where a > 0. Find the value of a so that the area of the region R is 18 square units.

Question 7 options:

1)	3
2)	3.772
3)	4.242
4)	9

Answer 1

Draw and label a diagram!!

f(x) = 2x + a → y-intercept is (0, a)

f(a) = 3a → corner at (a, 3a)

A trapezoid is formed

18 = (0.5)(3a + a)(a)

Can you solve for a and answer?