Word Problem

Question

Juliana, Rex, and Bobby work at the local Walmart selling newspapers and coupon books. One day, 3 of them had a combine sales total of $1480. Juliana sold $120 more than Rex. Rex and Bobby sold $280 more then Juliana. How much did each person sell?

Answer 1

J+R+B = 1480

J=120+R

R+B=280+J

3 equations, 3 unknowns, should give a unique solution

Matrix algebra is one method. Or just add and subtract & multiply to isolate one variable

Substitute the 2nd into the 3rd to get

R+B = 280 + 120 + R, now you're down to just 2 unknowns, get down to 1, and you can solve it

Cancel the R's to get

B= 280 + 120 = 400

R+B = 280 + J

R+400=280+J

R+120 = J

J+R+B = 1480

R+120 + R + 400 = 1480

2R= 1480 - 520 = 960

R = 480

J+R+B= 1480

J+480 + 400 = 1480

J= 1480 - 480 - 400 = 600

J= 600

J= 600, B = 400 R = 480