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

Answer:

$84

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

$\frac{2}{3}J = L -90$

$J + L = 300$

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

$\frac{2}{3}J = L - 90$

$\frac{2}{3}J + 90 = L$

          ↓

$J + \frac{2}{3}J + 90 = 300$

Now, we solve the 2-variable equation above:

$J + \frac{2}{3}J + 90 = 300$

$J + \frac{2}{3}J = 300 - 90$

$J + \frac{2}{3}J = 210$

$J(3) + (\frac{2}{3}J)(3) = 210(3)$

$3J + 2J = 630$

$5J = 630$

$J = \frac{630}{5}$

$\bf~J = 126$

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 $\frac{3}{3}$ of his money (total money).

So, if Jim has $126, which corresponds to $\frac{3}{3}$ of his money, $\frac{2}{3}$ of his money is:

$\frac{126}{3} = 42$

$126 * \frac{2}{3} = 42 + 42$

$\bf~126 * \frac{2}{3} = 84$

Hope it helped,

BiologiaMagister