Answer:c)21
Step-by-step explanation:
i just took the quiz
At first, we need to find x.
QR = LN
2x+1 = 3x-7
x=8
Substitute value of a=8 into QR = 2x+1.
QR = 2*8+1 = 17
QR =17
15.1 is close to 14 so then you have 14/7 which approximately = 2
When rounding the 4 you look to the right of the number, which is the 4, and if the number is higher than 5 you would change the 4 to 5.
Therefore: 71.5