John is twice as old as mary. the sum of their ages is 21. how old is mary?

let j = john's age and m = mary's age. select the system equations that represents the problem.

a. j - 2m = 0
b. m - 2j = 0
c. j + m = 21
d. j = m + 2

Carl wants to buy a television that cost $500 including taxes. to pay for television he will use a payment plan that requires him to make a down payment of $125 and then pay $70.50 each month for six months what is the percent increase from the original cast of the television to the cost of the television using a payment plan.

Eis the midpoint of line segment ac and bd also line segment ed is congruent to ec prove that line segment ae is congruent to line segment be

How many solutions does the nonlinear system of equations graphed bellow have?