The answer wold be 5(2)+5(7)
To find the inverse, interchange the variables and solve for y.
f^−1(x)=−25+5x/2
Try this suggested option, answers are marked with colour.
For this case we have:
Cost of manufactures of T-shirts 
where x represents the number of T-shirts
Part A:
Substituting 
in the total cost equation you have to:
Thus, the cost of 8 shirts will be 
Part B:
If 
then
Thus, the cost of 12 shirts will be 
Answer:
250 and - 1250
This is a geometric sequence with common ratio r = - 5
multiply each term by - 5 to obtain the next term
- 50 × - 5 = 250
250 × - 5 = - 1250
the sequence is - 2, 10, - 50, 250, - 1250
