Answer: 30
Explanation:
7a+4b-2c
First replace the variable and put in parentheses:
7(8)+4(2)-2(17)
When you see a number next to a parentheses, you multiply:
7(8)+4(2)-2(17)
56 + 8 - 34
Then you add first, and then subtract last:
55+8-34
64-34= 30
REMEMBER to use PEMDAS