Any one know how to do this my son need help

B) Profit per shirt goes from $10 to $15

Explanation:

Focus on the two points (2,0) and (3,10). The slope of the line through these points is

m = (y2-y1)/(x2-x1)

m = (10-0)/(3-2)

m = 10

Meaning the profit per shirt for this line is $10 per shirt.

Now move onto the other line. Focus on the points (9,40) and (11,70)

m = (y2-y1)/(x2-x1)

m = (70-40)/(11-9)

m = 15

The profit per shirt has gone up to $15 per shirt

john earns $14.00 for two hours of work.

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)