The first blank on the left side should be 0 I think
Answer: D
Explanation:
Since we don't know the y-value of the vertex, let's do this an easy way: plugging in.
Let's use the y intercept since that would be the easiest. Since x=0, the terms with x cancel, and you will get a leading result of -5
A) results in 2, so eliminate it
B) results in -2, so eliminate it
C) results in 5, so eliminate it
D) results in -5, so keep it
Since D was the only one that worked, that is our correct answer.
You do the sum(40) subtracted by 8, the answer from that divided by 2 since Erin's two times younger.
40-8=32
32÷2=16
Then if you want to check it you do the opposite and get the same sum(40) so 16×2=32 and 32+8=40
If its 20 more than last month that means x + $20 = $70, solve that and you get x = $50, last month she saved $50