Answer:
$8.65
Step-by-step explanation:
138.40/16 = 8.65
cos60⁰=3/y
y×cos60⁰=3
y=3/cos60⁰
y=3/0.5
y=6
y²=x²+3²
6²=x²+3²
36=x²+9
x²=36-9
x²=27
x=square root of 27
x=5.19
M+R=21
M+18=21
M=3
he left 3 magazines out to read
If brainiest is earned its greatly Appreciated