5x - [ -4x + 5 + {6x- (3+5x)}]

i hope this is what you were looking for.

see attached graph

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

so first lets findout how much she spent so whats 32.00 - x = 9.20

32.00 - 22.75 =9.25. so she spent a total of $22.75 okay now we know the amount she spent. so now u got it from here.