Martha recieved a commission of 7% for every car she sells. She sold a car for $5,625. What was her commission?

$393.75.

Step-by-step explanation:

Multiply 5,625 by 0.07 to find the comission amount.

i'm assuming that it's c.)   volcanoes built the mountains and earthquakes tore them down.

this is a direct variation proportion. y = kx

y is the total amount due, k is the constant of variation, and x is the number of texts sent.

plug in the 3.20 and the 16 to solve for the "k". this is the constant of proportionality. it is the value that will not change.

3.20 = k(16). solving you get $.20 per text.

the equation would then be y = .20x