You need to know these two formulas:

For example,

Answer:
SORRY IF IM WRONG BUT I THINK ITS C
Step-by-step explanation:
PLEASE MARK BRAINLIEST REMOVE MY ANSWER IF WRONG!!!!!!!!
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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Answer:
now i know my abc's
Step-by-step explanation:
Answer:
1
1
3
3
Step-by-step explanation: just cuz