4.509 is greater that 4.508 and less than 4.512
1.78 is the correct answer.
x y
1 290
2 280
3 270
4 260
5 250
6 240
7 230
8 220
9 210
10 200
11 90
12 180
13 170
14 160
15 150
16 140
17 130
18 120
19 110
20 100
21 90
22 80
23 70
24 60
25 50
26 40
27 30
28 20
29 10
30 0
Peter will have $910 - $40 * x on his account, where x is the number of the weeks. Marla will have $470 - $20 * x.
910 - 40 x = 470 - 20 x
910 - 470 = 40 x - 20 x
440 = 20 x
x = 440 : 20
x = 22
910 - 40 * 22 = 910 - 880 = $30
470 - 20 * 22 = 470 - 440 = $30
Answer: Their accounts will be equal in 22 weeks ( both of them will have $30 ).