Answer:
I solve it by substitution
y=x^2+4x
-x^2+9x+(x^2+4x)+13=0
13x+13=0
13x=-13
x= -13/13
x= -1
y=x^2+4x=1-4
y= -3
Step-by-step explanation:
Answer:
Step-by-step explanation:
If you subtract the extra 12 quarters from the total, you have $4.55 that can be made up of groups of 1 quarter and 1 dime. Since those groups are worth $0.35, there are $4.55/$0.35 = 13 of them.
There are 13 dimes and 13+12 = 25 quarters in the purse.
<span>To determine the Area, A, we just multiply the two sides together:
A = (x - 1) (x + 4)
A = x^2 - 1x + 4x - 4
A = X^2 + 3x - 4</span>