Answer:
x = 5
Step-by-step explanation:
4x + 2y + z = 24
2x - 3y - z = 2
5x + y + 2z = 21
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Eliminate z
Add the 1st and 2nd eqn
4x + 2y + z = 24
2x - 3y - z = 2
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6x - 1y = 26 eqn A
Multiply the 2nd eqn by 2, then add the 3rd.
4x - 6y -2z = 4
5x + y + 2z = 21
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9x - 5y = 25 eqn B
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Now you have 2 eqns in 2 unknowns, not 3.
Multiply eqn A by 5 and subtract eqn B.
30x - 5y = 130 eqn A times 5
9x - 5y = 25 eqn B
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21x = 105
x = 5
I think it is 9 - x because 81-x^2/9-x = 9-x
Answer:
10
Step-by-step explanation:
For every lawn mowed, the amount earned increases by 10 dollars
Answer:
-4 sqrt(7)/7
Step-by-step explanation:
csc theta = -4/3
csc theta = hypotenuse / opposite side
hypotenuse = 4
opposite = 3
Using the pythagorean theorem
a^2 + b^2 = c^2
3^2 + b^2 = 4^2
9+b^2 = 16
b^2 = 16-9
b^2 = 7
Taking the square root
sqrt(b^2) = sqrt(7)
b = sqrt(7)
We are in the third quadrant so only tan and cot are positive
that means the x and y values are "negative" so a = -3 and b = - sqrt(7)
sec theta = hypotenuse / adjacent
= 4/ - sqrt(7)
rationalizing
-4 sqrt(7)/ sqrt(7)* sqrt(7)
= -4 sqrt(7)/7
