Answer:
B
x is the price of the sweater so 3x and add $15 for the skirt which would add up to $90
The value of k is
<h3>How to solve the simultaneous equation?</h3>
Given:
x-y=k.............(eq i)
2x²+y²-15..............(eq ii)
We would make y the subject formula in eq ii
2x²+y²-15= 0
2x² + y²= 15
y²= 15-2x²
y=
...........(eq iii)
Substitute the value of y into eq i
x-(
= k
x- (
= k
k= 
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