Question

jim and lisa had a total of $300. After jim boughy a jacket with 2/3 if her money,she had $90 less than lisa. find the cost of the jacket.​

Answer 1

$84

Firstly, what we must do, is establish a system of equations:

`(2)/(3)J = L -90`

`J + L = 300`

Due the circumstances, it is decided we will use the method of substitution:

`(2)/(3)J = L - 90`

`(2)/(3)J + 90 = L`

↓

`J + (2)/(3)J + 90 = 300`

Now, we solve the 2-variable equation above:

`J + (2)/(3)J + 90 = 300`

`J + (2)/(3)J = 300 - 90`

`J + (2)/(3)J = 210`

`J(3) + ((2)/(3)J)(3) = 210(3)`

`3J + 2J = 630`

`5J = 630`

`J = (630)/(5)`

`\bf~J = 126`

Now, we must see how much money each one of them had & the price of the jacket:

Now we know that Jim had $126. In other words, $126 is
`(3)/(3)` of his money (total money).

So, if Jim has $126, which corresponds to
`(3)/(3)` of his money,
`(2)/(3)` of his money is:

`(126)/(3) = 42`

`126 * (2)/(3) = 42 + 42`

`\bf~126 * (2)/(3) = 84`

Hope it helped,

BiologiaMagister