— 57 = — 3х + 3 (5х +9)

the answer is -6

step-by-step explanation:

the answer is -6 because its next to the variable m

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

the first domain and range set to the left is matched with the top relation, and the second set the set in the middle goes with the bottom relation.