Question

Mari and Jen each work 20 hours a week at different jobs.Mari earns twice as much as Jen.Together they earn $480.How much does each girl earn in a week

Answer 1

m=2j
m+j=480
Substitute 2j for m;
2j+j=480
3j=480
j=160
Jen earns $160 per week.
m=2j
m=2(160)
m=320
Mari earns $320 per week.