The total proceeds from a used book sale were $\$155$ a total of 65 books were sold the books were priced at $\$3$ and $\$2$ each . How many books were sold for $\$3$? How many books were sold for $\$2$?
+2401
Let X stand for the number of $2 books
Let Z stand for the number of $3 books
X + Z = 65 multiply both sides by 3 —> 3X + 3Z = 195
2X + 3Z = 155 —> 2X + 3Z = 155
subtract X = 40 books @ $2
X + Z = 65 —> 40 + Z = 65
Z = 65 – 40
Z = 25 books @ $3
check answer
does 2•40 + 3•25 = 155 ?
80 + 75 = 155 ?
155 = 155 true
.
