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:
50 nickels, 20 quarters.
Step-by-step explanation:
System of equations (q = # of quarters, n = # of nickels):
<em>q + n = 70, 0.25q + 0.05n = 7.50</em>
the first equation can be changed to q = 70 - n, so we are able to <em>substitute q with 70 - n</em>.
So, it will look like <em>0.25*70 - 0.25n + 0.05n = 7.50</em>. This can be simplified to <em>0.2n = 10</em>, which means that n = 50.
Knowing that we can solve <em>q + 50 = 70</em>, which means that q = 20.
Answer:

Step-by-step explanation:
1) Add 6 to both sides.

2) Simplify 21 + 6 to 27.

3) Divide both sides by 9.

4) Simplify 27/9 to 3.

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Answer:
Step-by-step explanation:
You do this by figuring out the amounts of pure fruit juice in all.
Explanation:
Mixture:
17 gal 30% contains:
17
⋅
30
100
=
5.10
gal pure juice
From Brand B:
8 gal 48% contains:
8
⋅
48
100
=
3.84
gal pure juice
So
5.10
−
3.84
=
1.26
gal came from 9 gal of brand A
So the percentage of A is:
1.26
9
⋅
100
=
14
%
pure juice.
Mark brainliest if this answer is correct please