For which equation is m = 12 the solution? a. 4m=40 b. m+20=42. c. 4m=48. d. m-4=9

To solve this question, we just need to insert 12 into the m position of each question and see if the equation holds true.

a. 4m = 40

4(12) = 40

48 = 40

48 obviously does not equal 40, so it is not choice A.

b. m + 20 = 42

12 + 20 = 42

32 = 42

Again, 32 isn't the same as 42, so not choice B either.

c. 4m = 48

4(12) = 48

48 = 48

It looks like this one is true, but let's solve D also just to make sure.

d. m - 4 = 9

12 - 4 = 9

8 = 9

This is false, since 8 does not equal 9.

Therefore, choice C (4m = 48) is the correct answer.
Hope that helped! =)