Plug in the point for each equation:
x=1/4y + a
(1)=1/4(2) + a
1=1/2+a
1/2=a
y=1/4x+b
2=1/4(1) +b
b= 7/4
Solve a+b:
a+b=?
(2/4)+(7/4)= 9/4= 2.25
IO/2.4 = I5/x
IOx = 36
x = 3.6
As a decimal, that is 17.625, which rounds up to 18.
8. 6 hours because 60(6) + 120=480
9. third one down because she scored 18 or. higher
The interest is 3.5 percent or 3 percents of the sum she deposited.