Describe how to model - 3x + 7 = 28

To model - 3x + 7 = 28, you have to find the additive inverse of 7. Since - 7 is the additive inverse of 7, you subtract both sides by - 7 and you bring down - 3x and the = sign. Make sure you draw a long line beneath the equation. Cross out the - 7 and 7. So 28 - 7 is 21. Next is to find the multiplicative inverse of - 3x. So - 3x = 21 is - 7. Before that, you divide both sides by 3 and cancel out the - 3x/3. Bring down x and = and your answer is - 7. x = - 7

AWell the answer is - 7

you minus 28 from 7 and get 21. so divide 21 by - 3 and you get - 7.