Solve equation elimination method
8y-3x=5xy , 6y-5x=-2xy
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Answered by
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we eliminate the xy term.
8 y - 3 x = 5 x y --- equation (1)
6 y - 5 x = - 2 x y ---- equation (2)
multiply (1) by 2 and multiply (2) with 5 and then add,
16 y - 6 x + 30 y - 25 x = 10 x y - 10 x y
46 y - 31 x = 0
so y = 31/46 * x --- (3)
substitute this value of y in (1).
8 * 31/46 x - 3 x = 5 x * (31/46 x)
multiply by 46 and divide by x :
248 - 138 = 155 x
x = 110 / 155 = 22/31
y = 31/46 * 22/31 = 11/23
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another way:
Divide equations (1) and (2) by xy:
8 / x - 3 / y = 5 and 6 / x - 5 / y = - 2
call 1/x = X and 1/y = Y
8 X - 3 Y = 5 --- (3)
6 X - 5 Y = -2 --- (4)
we eliminate X by (3) * 3 - (4) * 4
24 X - 9 Y - 24 X + 20 Y = 15 + 8
11 Y = 23
=> Y = 23 /11 => y = 11/23
substitute this in (3)
8 X - 3 * 23 /11 = 5
8 X = 5 + 69/11 = 124/11
X = 31/22
=> x = 22/31
8 y - 3 x = 5 x y --- equation (1)
6 y - 5 x = - 2 x y ---- equation (2)
multiply (1) by 2 and multiply (2) with 5 and then add,
16 y - 6 x + 30 y - 25 x = 10 x y - 10 x y
46 y - 31 x = 0
so y = 31/46 * x --- (3)
substitute this value of y in (1).
8 * 31/46 x - 3 x = 5 x * (31/46 x)
multiply by 46 and divide by x :
248 - 138 = 155 x
x = 110 / 155 = 22/31
y = 31/46 * 22/31 = 11/23
=========================
another way:
Divide equations (1) and (2) by xy:
8 / x - 3 / y = 5 and 6 / x - 5 / y = - 2
call 1/x = X and 1/y = Y
8 X - 3 Y = 5 --- (3)
6 X - 5 Y = -2 --- (4)
we eliminate X by (3) * 3 - (4) * 4
24 X - 9 Y - 24 X + 20 Y = 15 + 8
11 Y = 23
=> Y = 23 /11 => y = 11/23
substitute this in (3)
8 X - 3 * 23 /11 = 5
8 X = 5 + 69/11 = 124/11
X = 31/22
=> x = 22/31
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Answered by
1
Answer:
x = 22/31
x = 22/31y=23/11
Step-by-step explanation:
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