She will pay 90 because the income is 5 times greater
(answer o number one)
Solve it by substitution. First let's rewrite the first equation (3x+4y=16) so we have y = something, then we'll substitue that in to the other equation.
3x+4y=16
4y=-3x+16
y=-3/4x+4
Now we can substitute this into the other equation.
Y = -2/3x + 7.....the slope here is -2/3. A perpendicular line will have a negative reciprocal slope. All tht means is take the original slope, flip it, and change the sign. So we take -2/3....flip it making it -3/2.....change the sign making it 3/2. So ur perpendicular line will have a slope of 3/2.
y = mx + b
slope(m) = 3/2
(-5,6)....x = -5 and y = 6
now sub and find b, the y int
6 = 3/2(-5) + b
6 = -15/2 + b
6 + 15/2 = b
12/2 + 15/2 = b
27/2 = b
so ur perpendicular equation is : y = 3/2x + 27/2 <==
The answer it Curve Fitting or Arc but I think Curve Fitting just good luck