Question

Joy and Cullen put some money into their money boxes every week. The amount of money (y), in dollars, in their money boxes after a certain amount of time (x), in weeks, is shown by the equations below:

Joy: y = 30x + 20
Cullen: y = 20x + 90

After how many weeks will Joy and Cullen have the same amount of money in their money boxes, and what is that amount?

6 weeks, $150
230 weeks, $7
7 weeks, $150
7 weeks, $230

Answer 1

its not A and C

Answer 2

I think it is B

Answer 3

y = 30x + 20
20x + 90 = 30x + 20 ... Replace y with 20x+90
20x + 90 - 90 = 30x + 20 - 90 ... Subtract 90 from both sides.
20x + 0 = 30x - 70
20x = 30x - 70
20x = -70 + 30x
20x - 30x = -70 + 30x - 30x ... Subtract 30x from both sides.
-10x = -70 + 0x -10x = -70 x = ?

Answer 4

urf idk

Answer 5

urf?

Answer 6

urf just meaning gosh idk

Answer 7

oh x=7

Answer 8

so it is D?

Answer 9

Yep

Answer 10

thx

Answer 11

No problem