Barb has $800 and is spending $30 per week. Claire has $300 and is saving $20 per week. In how many week ,will Bard and Claire have the same amount of money?

10 weeks

Let x represent weeks
Barb: 800-30x
Claire: 300+20x

Set the 2 equations equal to each other
800-30x=300+20x

Add the 30x over
800=300+50x

Subtract the 300 over
500=50x

Divide by 50 on both sides

x=10
After 10 weeks they will have the same amount of money.

Hope this helps!