Answer:
6th week with $32
Step-by-step explanation:
Since both plan on adding or spending money weekly at a constant rate, this is a linear situation. Both Tommy's and Joey's money can be modeled with a line on a graph and linear equations.
Tommy's starting amount is $8 and this is the y-intercept so b=8. His rate of change is adding $4 per week. This is a slope of 4. His equation is y=4x+8.
Joey's starting amount is $44 and this is the y-intercept so b=44. His rate of change is subtracting $2 a week for each app he buys. This is a slope of -2. His equation is y=-2x+44.
To find when they have the same amount means when the amounts are equal. Solve 4x+8=-2x+44.
4x+8=-2x+44
6x+8=44
6x=36
x=6 weeks
To find how much money there is in 6 weeks, plug x=6 into one of the equations.
4(6)+8 = 24+8 = 32
