No, it is not. If you plug 4 into the equation in the place of x, you get 13=2(4)+4
13=8+4
13=12
It equals 12, not 13.
Answer:
How pooor are you it'svery hard
Answer:

Step-by-step explanation:
Set up the equation:
Since C(t) gives the number of cars purchased in the t-th year after 1998, then make the number of cars equal to 15 000 and solve for t - the year:
20t^2 = 15000
t^2 = 750
t = 
The year will be simply 1998 + 5 \sqrt{30}
Answer:
x=-25
Step-by-step explanation:
35=-2x-15
add 15 to both sides, cancels the 15 from the right
50=-2x
divide both sides by -2, isolates the x
-25=x