Answer:
15 weeks
Explanation:
1 write an equation fore each
you sister
y=25+3x y=40+2x
y is total money and x is weeks
we want to find when they have the same amount of total money we set them equal to echother
25+3x=40+2x
-2x -2x
25+x=40
-25 -25
x=15
you will have the same amount as yore sister in 15 weeks