Having trouble understanding how to solve this math problem. Please help.

Question

The amount of food energy required by a busy courier is given by the formula E = -125T + 15250. E is the amount of food energy in kilojoules. T is the outside temperature in degrees Celsius. Find the outside temperature when 10250kJ of food energy is required.

Answer 1

E = -125T + 15250

Since E is the amount of food energy in kilojoules and they give you 10250kJ

plug that in for E and solve for T

10250= -125T + 15250

Subtract 15250 from both sides

-5000=-125T

Divide both sides by -125

T=40