I believe the answer is 55.
Answer: $27.87
Explanation: if it is 1 by 2 you would multiply 1 x 2 and get 2 then multiply 13.87 x 2 to get 27.87 and it leaves you with $27.87
Line k has a slope of -7/-2 a perpendicular lines slope is equal to the opposite reciprocal of line k. Therefore line r has a slope of 2/7 or y=2/7
3=21/(x+5)
Cross multiply
3(x+5)=21
Divide 3
X+5 = 7
Subtract 5
X= 2