X^2 - 8x-9=0
D = b^2- 4*a*c = 64- 4* (-9) = 64+36=100 =10^2
X1 = (8-10)/2 = -1
X2= (8+10)/2= 9
It would be 28-10=x because your ending up with 28 after earning 10 you would get that. Hope this works!
I’m thinking your r in the first equation is actually an x.
X + 2(2x -4) =10
X +4x -8 =10
5x = 18
You would take d times t seconds and find the answer
Answer:
1
Step-by-step explanation:
x-7=-5x-1
x-(-5x)-7=-1
x+5x-7=-1
6x-7=-1
6x=-1+7
6x=6
x=6/6
x=1
