Math help pleaseee it's due tomorrow

Question

i have to do this retarded summer math packet there's this one word problem i can't figure out.

write a system of equations and solve. Be sure to define the variables used. Megan exercises every morning for 40 minutes. She does a combination of step aerobics, which burns 11 Calories per minute, and stretching, which burns 4 Calories per minute. Her goal in to burn 335 Calories during her routine. How long should she spend on each type of exercise to reach her goal.

thanks so much!!

Answer 1

x = time doing step aerobics

y = time stretching

11x + 4y = 335  <-- number of calories burned

x + y = 40   <--- total time spent

2 equations, 2 unknowns so solve for x and y:

x = 40-y

11(40-y) + 4y = 335

440 - 7y = 335

y = 15 minutes

x = 40-y = 25 minutes

Answer 2

Learn to do math.