9514 1404 393
Answer:
2/3
Explanation:
Let x represent the fraction of Cheryl's income she spent in September. Then 1-x is the fraction she saved.
In October, her spending increased by 0.2x, and her savings decreased by 0.4(1 -x). Since Cheryl spends or saves all of her income, these two change amounts must be equal:
0.2x = 0.4(1 -x)
x = 2(1 -x) . . . . . . multiply by 5 to clear fractions
x = 2 -2x . . . . . . eliminate parentheses
3x = 2 . . . . . . . . add 2x
x = 2/3 . . . . . . divide by 3
Cheryl spent 2/3 of her income in September.