Answer:
$34
Step-by-step explanation:
I'd work backwards.
For the third book, she paid all her remaining money. The problem says she paid "1/2 her leftover money + $3". This means that: (let m = money used to buy book 3)
m = 1/2m + 3
1/2m = 3
m = 6
For the second book: (let n = money before book 2)
n - m (money left after book 2) = 1/2n + 2
1/2n +2 is money used up for book, which is the same as n-m.
n = 1/2n + 2 + m
1/2n = 2 + m = 2 + 6
1/2n =8
n = 16
For the first book, she spent 1/2 her money + 1. If o = money before book 1 (or the whole allowance):
o - n = 1/2o + 1
o = 1/2o + n + 1 = 1/2o + 16 + 1
1/2o = 17
o = 34
Check!
Spent 17 (half 34) + 1 on book 1
16 left
Spent 8 (half 16) +2 on book 2
6 left
Spent 3 (half 6) + 3 on book 3
0 left
Answer:
Step-by-step explanation:
Since, the variables x and y are inversely proportional.
First, let's multiply the first equation by two. This is because we have to eliminate either x or y by subtraction or addition so that means either both of the x's or both of the y's in the two equations have to be equal. Thus multiplying the first equation by 2 will give 12x+8y=4.
Next, subtract equation two from equation one:
We get a third equation, 2x-0= -28
Thus, x=-28/2. x= -14
In the same way, to find y, we need to eliminate the x's in both equations. This can be done by multiplying the first equation by 5 and the second by 3
Thus : 30x+20y=10 and 30x-24y=96
Subtracting the second equation from the first, we have 0+44y=-86
y=-86/44
y = 1.96 or 43/22
That is called an equation
