y = 12x + 10
Assuming that your question is multiple choice, the variables might be different.
The reason that it's represented as 12x + 10 is because there is a flat fee of $10 when you sign up. From then on afterward, every month you pay $12.
In this equation, the variable 'y' represents the total cost, while 'x' represents the number of months this service was in use.
So, the anti derivative= x^2 -.8x +C. Ignore C.
Plug in 2= 4-(2)(.8)=2.4
Plug in .4= .16-(.4)(.8)=-.16
2.4-(-.16)= 2.56
Answer: 32 meters
Explanation: The 4 meter pole casts a shadow of 5 meters. The towers unknown height casts a shadow of 40 meters. Now isolate the shadows. 5 and 40. 40 divided by 5 is 8, so 4 times 8 is 32.
