Which equation can be used to find the answer?
After two months, Rachel has saved enough money to buy an MP3 player. During the second month, she saved $87 and she pays $199 for the MP3 player.
How much did Rachel save during the first month?
a. m = 87 • 2
m = 174
$174
b. 199 + 87 = m
m = 286
$286
c. m + 87 = 199
m = 112
$112
d. m – 87 = 199
m = 287
$287