2007-05-07 08:51:46 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
system of equations solution
2x + y = 7 - - - - - Equation 1
3x - 2y = 4- - - - - Equation 2
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Multiply equation 1 by 2
2x + y = 7
2(2x) + 2(y) = 2(7)
4x + 2y = 14
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Elimination of y
4x + 2y = 14
3x - 2y = 4
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7x = 18
7x / 7 = 18 / 7
x = 18 / 7
Insert the x value into the equation 1
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2x + y = 7
2(18/7) + y = 7
36 / 7 + y = 7
36/7 + y - 36/7 = 7 - 36/7
y = 49/7 - 36/7
y = 13/7
Insert the y value into equation 1
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Check for equation 1
2x + y = 7
2(18/7 + 13/7 = 7
36/7 + 13/7 = 7
49/7 = 7
7 = 7
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Check for equation 2
3x - 2y = 4
3(18/7) - 2(13/7) = 4
54/7 - 26/7 = 4
28/7 = 4
4 = 4
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Both equations balance
The x value is 18/7
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2007-05-07 10:20:44 · answer #1 · answered by SAMUEL D 7 · 1⤊ 0⤋
1. Multiply first eq with 2
4x+2y=14
2. Add the equations
7x = 18
3. Solve for x
x=18/7
2007-05-07 08:58:24 · answer #2 · answered by ulfsnilsson 2 · 0⤊ 1⤋
2x+y =7
3x-2y =4
use linear combination to get that 7x=18
x= 18/7
2007-05-07 08:57:38 · answer #3 · answered by Britt L 2 · 0⤊ 1⤋