Explanation:
let us keep the price of pants as x
and price of necklace as y
Simultaneous equations comes as follows:
4x + 3y = 216 for Alexis
7x + 2y = 300 for Jess
we'll make either x or y equal
here let's make y equal
2 ( 4x + 3y = 216)
3 ( 7x + 2y = 300)
8x + 6y = 432
21x + 6y = 900
21x - 8x = 900 - 432
13x = 468
x = $36
so a pant costs $36
And
3y = 72
y = $ 24
so a necklace costs $36