Answer:
(x, y) = (1/2, -1)
Step-by-step explanation:
Subtracting twice the first equation from the second gives ...
(2/x +1/y) -2(1/x -5/y) = (3) -2(7)
11/y = -11 . . . . simplify
y = -1 . . . . . . . multiply by y/-11
Using the second equation, we can find x:
2/x +1/-1 = 3
2/x = 4 . . . . . . . add 1
x = 1/2 . . . . . . . multiply by x/4
The solution is (x, y) = (1/2, -1).
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<em>Additional comment</em>
If you clear fractions by multiplying each equation by xy, the problem becomes one of solving simultaneous 2nd-degree equations. It is much easier to consider this a system of linear equations, where the variable is 1/x or 1/y. Solving for the values of those gives you the values of x and y.
A graph of the original equations gives you an extraneous solution of (x, y) = (0, 0) along with the real solution (x, y) = (0.5, -1).
Answer:
1.6 gallons (so if you can only buy by the gallon, 2 gallons)
Step-by-step explanation:
You divide the total area by how much a gallon covers to get the number of gallons needed.
40/25=1.6
N = nickels and q = quarters
0.05n + 0.25q = 1.90
n = 2q + 3
0.05(2q + 3) + 0.25q = 1.90
0.10q + 0.15 + 0.25q = 1.90
0.10q + 0.25q = 1.90 - 0.15
0.35q = 1.75
q = 1.75/0.35
q = 5 ......there are 5 quarters
n = 2q + 3
n = 2(5) + 3
n = 10 + 3
n = 13 <=== there are 13 nickels
Answer:
≈ 30.63 cm²
Step-by-step explanation:
The shaded area is calculated by subtracting the area of the inner circle from the area of the outer circle.
outer circle has radius = 8 ÷ 2 = 4 and inner circle has radius = 5 ÷ 2 = 2.5
shaded area = πr₁² - πr₂² (r₁ is outer and r₂ is inner )
A = π (4² - 2.5²)
= π(16 - 6.25) = 9.75π ≈ 30.63 cm²
Answer:
(-8,5)
Step-by-step explanation:
The output corresponds to the y-value of an ordered pair while the input corresponds to the x-value of an order pair.
An ordered pair is written like this (x,y)
