Let's say x represents the number of weeks, and y the number of dollars. For Janelle, an equation to find out how much money she has is y = 20 + 6x. For April, the equation is y = 150 - 4x. Now we need to find how long it will take them to have the same amount of money, and how much that is. A new equation to figure that out is 150 - 4x = 20 + 6x. To solve, make it so the variable is only one side. Add 4x to both sides. You now get 150 = 20 + 10x. Then we continue solving. Subtract 20 from both sides to get 130 = 10x. Then divide both sides by 10 to get 13 = x. This means in thirteen weeks, they will have the same amount of money. To find out how much money they have, choose one (or both to be sure) of the equations and solve for y. For example, Janelle's equation is y = 20 + 6x. Fill in 13 for x to get y = 20 + 6(13). y = 20 + 78. y = 98. This means in 13 weeks, Janelle will have 98 dollars. To be sure, also check with April's equation. y = 150 - 4x. y = 150 - 4(13). y = 150 - 52. y = 98. Therefore, in 13 weeks, both people will have 98 dollars.
