An online bookstore sells all paperback books for x dollars each. Aidan bought 7 paperback books and spent $3.95 on shipping. Nina bought 11 paperback books and spent $5.25 on shipping. What expression represents the total amount that Aidan and Nina spent?

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

d

step-by-step explanation:

i used the pitagoras theoreme

soo this can be solve by using the formula:

f = p( 1 + i)^ n

where f is the future profit

p is the initial profit

i is the percent increase

n is the number of years

a . f = 30000 ( 1.05)^n

b. f = 30000 ( 1.05)^15

f = $62,368