You are saving $100 a week to buy a new computer. Your brother is saving at a weekly rate of 10x-2, if x = the number of weeks of saving. In how many weeks will

Question

You are saving $100 a week to buy a new computer. Your brother is saving at a weekly rate of 10x-2, if x = the number of weeks of saving. In how many weeks will you both have equal amounts of money?

Answer 1

100x = 10x-2

90x = -2

x =-2/90 = -1/45 weeks = negative less than one day

in 1 week you saved $100. in one week your brother saved $10-$2 = $8

in 2 weeks you save $200, and your brother saved $18

you start off in zero week with zero dollars while your brother has -$2.

in -1/45 part of a week, you have -$100/45 = -$20/9 =about - $2.22

while your brother has 10(-1/45)-2 = -10/45-90/45 =-100/45 =about -$2.22

You seem to both be in debt by $2.22 in a small fraction of a day prior to when you start saving money. 1/45 day = 24/45 = 5 1/3 hours

graph the two equations. They're straight lines that intersect at about the point (-1/45, -2.22) in quadrant 3

UNLESS the problem was copied incorrectly or printed incorrectly. It's likely the problem has a problem, maybe an incorrect sign or coefficient somewhere