Answer:
We start with the equation:
A: 3*(x + 2) = 18
And we want to construct equation B:
B: X + 2 = 18
where I suppose that X is different than x.
Because in both equations the right side is the same thing, then the left side also should be the same thing, this means that:
3*(x + 2) = X + 2
Now we can isolate the variable x.
(x + 2) = (X + 2)/3
x = (X + 2)/3 - 2
Then we need to replace x by (X + 2)/3 - 2 in equation A, and we will get equation B.
Let's do it:
A: 3*(x + 2) = 18
Now we can replace x by = (X + 2)/3 - 2
3*( (X + 2)/3 - 2 + 2) = 18
3*( (X + 2)/3 ) = 18
3*(X + 2)/3 = 18
(X + 2) = 18
Which is equation B.
p=15250
r=7.5/100=0.075
y = 15250*(1 - 0.075)^x
after 8 years it would be
x = 8
y = 15250*(1 - 0.075)^8
y = $8,173.42
after 8 years the value of the car is going to be $8,173.42
Child=x
Adult=y
y=3x
5.2x+9.9y=767.8
5.2x+9.9(3x)=767.8
5.2x+29.7x=767.8
34.9x=767.8
x=22
