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N76 [4]
3 years ago
14

If 3x+2y=12 and -4x+6y=24 what is the value of -x+2y

Mathematics
1 answer:
oksano4ka [1.4K]3 years ago
6 0
(1) 3x+2y=12
(2) -4x+6y=24

Solving the system of equations using the method of substitution:
Isolating y in the first equation:
(1) 3x+2y=12→3x+2y-3x=12-3x→2y=12-3x→2y/2=(12-3x)/2→y=(12-3x)/2

Replacing "y" by (12-3x)/2 in the second equation:
(2) -4x+6y=24
y=(12-3x)/2→-4x+6[(12-3x)/2]=24

Solving for x:
-4x+3(12-3x)=24
-4x+36-9x=24
-13x+36=24
-13x+36-36=24-36
-13x=-12
-13x/(-13)=-12/(-13)
x=12/13

Replacing "x" by 12/13 in y=(12-3x)/2
x=12/13→y=[12-3(12/13)]/2
y=(12-36/13)/2
y={[(13)(12)-36]/13}/2
y=[(156-36)/13]/2
y=(120/13)/2
y=(120/13)(1/2)
y=60/13

x=12/13; y=60/13
-x+2y=-12/13+2(60/13)
-x+2y=-12/13+120/13
-x+2y=(-12+120)/13
-x+2y=108/13

Answer: The value of -x+2y is 108/13 
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ASHA 777 [7]

The translation of the question given is

A line that passes through the points A (2,1) and B (6,3) and another line passes through A and through the point (0, y). What is y worth, if both lines are perpendicular?

Answer:

y = 5

Step-by-step explanation:

Line 1 that passes through A (2,1) and B (6,3)  

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y -1 = -2x +4

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7 0
2 years ago
10 km, 7 km, 13 km<br> Is the triangle acute, right, or obtuse
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Step-by-step explanation:

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Solve 19cos θ = 5 cos θ + 14 for all values of θ if θ is measured in radians.
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Answer:

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Step-by-step explanation:

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