Mika’s gym allows her to bring 3 guests for free. After the first three, she must pay $7 per guest. How many guests, g, can she bring to the gym if she pays $42? Three of these equations give the correct value of g. Which equation does NOT? 7g = 63 7(g – 3) = 42 7g – 3 = 42 g = 9

Okay. So 3 guests are free. Mika has $42 dollars she can spend with $7 per guest. 42/7 = 6. Add the 3 other guests and you get 9. Mika can bring 3 guests with her to the gym. D gives the correct answer, and A and B give out the correct equations as well. C is not right, because 7 * 9 is 63. 63 - 3 is 60. 60 > 42. C is the incorrect equation. The answer is C.