Using the cosine function:

Solve for b:
C. "David's equation is correct, because their spending will be multiplied by the number of months and then subtracted from their savings"
they are technically saying "Look we have 12,350 to use. How long (y) will the savings (12,350) last after using 240 each month (x)
so the amount they use *PER* month gets subtracted from the savings because they are using that money to pay with
Hope this helps :)
Answer:
y = 0.2
Step-by-step explanation:
Simplifying
-6y + 5 = 29y + -2
Reorder the terms:
5 + -6y = 29y + -2
Reorder the terms:
5 + -6y = -2 + 29y
Solving
5 + -6y = -2 + 29y
Solving for variable 'y'.
Move all terms containing y to the left, all other terms to the right.
Add '-29y' to each side of the equation.
5 + -6y + -29y = -2 + 29y + -29y
Combine like terms: -6y + -29y = -35y
5 + -35y = -2 + 29y + -29y
Combine like terms: 29y + -29y = 0
5 + -35y = -2 + 0
5 + -35y = -2
Add '-5' to each side of the equation.
5 + -5 + -35y = -2 + -5
Combine like terms: 5 + -5 = 0
0 + -35y = -2 + -5
-35y = -2 + -5
Combine like terms: -2 + -5 = -7
-35y = -7
Divide each side by '-35'.
y = 0.2
Simplifying
y = 0.2
Answer:
20%
Step-by-step explanation:
14/70x100=20%