detailed information: The input equation set is:
 | | | | A | + | | B | + | | C | + | | D | + | | E | + | | F | + | | G | = | | 103 | | (1) |
| | 4 | B | | -1 | C | + | | 4 | D | | -1 | E | + | | 3 | F | + | | 3 | G | = | | 0 | | (2) |
| | | | | | Question solving process:
Add both sides of equation (1) to both sides of equation (3) ,the equations are reduced to:
 | | | | A | + | | B | + | | C | + | | D | + | | E | + | | F | + | | G | = | | 103 | | (1) |
| | 4 | B | | -1 | C | + | | 4 | D | | -1 | E | + | | 3 | F | + | | 3 | G | = | | 0 | | (2) |
| | B | + | | 2 | C | + | | E | + | | 2 | F | + | | G | = | | 98 | | (3) |
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Divide the two sides of equation (2) by 4, the equation can be obtained: | | B | | - | 1 4 | C | + | | D | | - | 1 4 | E | + | | | 3 4 | F | + | | | 3 4 | G | = | | 0 | (8) | , then subtract both sides of equation (8) from both sides of equation (3), the equations are reduced to:
 | | | | A | + | | B | + | | C | + | | D | + | | E | + | | F | + | | G | = | | 103 | | (1) |
| | 4 | B | | -1 | C | + | | 4 | D | | -1 | E | + | | 3 | F | + | | 3 | G | = | | 0 | | (2) |
| | | 9 4 | C | | -1 | D | + | | | 5 4 | E | + | | | 5 4 | F | + | | | 1 4 | G | = | | 98 | | (3) |
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Add both sides of equation (4) to both sides of equation (3), get the equation:
 | | | | A | + | | B | + | | C | + | | D | + | | E | + | | F | + | | G | = | | 103 | | (1) |
| | 4 | B | | -1 | C | + | | 4 | D | | -1 | E | + | | 3 | F | + | | 3 | G | = | | 0 | | (2) |
| | | 9 4 | C | + | | | 9 4 | E | + | | | 9 4 | F | + | | | 5 4 | G | = | | 156 | | (3) |
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Multiply both sides of equation (4) by 4, get the equation: | | 4 | D | + | | 4 | E | + | | 4 | F | + | | 4 | G | = | | 232 | (9) | , then subtract both sides of equation (9) from both sides of equation (2), get the equation:
 | | | | A | + | | B | + | | C | + | | D | + | | E | + | | F | + | | G | = | | 103 | | (1) |
| | 4 | B | | -1 | C | | -5 | E | | -1 | F | | -1 | G | = | | -232 | | (2) |
| | | 9 4 | C | + | | | 9 4 | E | + | | | 9 4 | F | + | | | 5 4 | G | = | | 156 | | (3) |
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Subtract both sides of equation (4) from both sides of equation (1), get the equation:
 | | | | | 4 | B | | -1 | C | | -5 | E | | -1 | F | | -1 | G | = | | -232 | | (2) |
| | | 9 4 | C | + | | | 9 4 | E | + | | | 9 4 | F | + | | | 5 4 | G | = | | 156 | | (3) |
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Multiply both sides of equation (3) by 4 Divide both sides of equation (3) by 9, get the equation: | | C | + | | E | + | | F | + | | | 5 9 | G | = | | | 208 3 | (10) | , then add the two sides of equation (10) to both sides of equation (2), get the equation:
 | | | | | 4 | B | | -4 | E | | - | 4 9 | G | = | | - | 488 3 | | (2) |
| | | 9 4 | C | + | | | 9 4 | E | + | | | 9 4 | F | + | | | 5 4 | G | = | | 156 | | (3) |
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Multiply both sides of equation (3) by 4 Divide both sides of equation (3) by 9, get the equation: | | C | + | | E | + | | F | + | | | 5 9 | G | = | | | 208 3 | (11) | , then subtract both sides of equation (11) from both sides of equation (1), get the equation:
 | | | | A | + | | B | | -1 | E | | -1 | F | | - | 5 9 | G | = | | - | 73 3 | | (1) |
| | 4 | B | | -4 | E | | - | 4 9 | G | = | | - | 488 3 | | (2) |
| | | 9 4 | C | + | | | 9 4 | E | + | | | 9 4 | F | + | | | 5 4 | G | = | | 156 | | (3) |
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Divide both sides of equation (2) by 4, get the equation: | | B | | -1 | E | | - | 1 9 | G | = | | - | 122 3 | (12) | , then subtract both sides of equation (12) from both sides of equation (1), get the equation:
 | | | | | 4 | B | | -4 | E | | - | 4 9 | G | = | | - | 488 3 | | (2) |
| | C | + | | E | + | | F | + | | | 5 9 | G | = | | | 208 3 | | (3) |
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The coefficient of the unknown number is reduced to 1, and the equations are reduced to:
 | | | | | | C | + | | E | + | | F | + | | | 5 9 | G | = | | | 208 3 | | (3) |
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Therefore, the solution of the equation set is:
Convert the solution of the equation set to decimals:
 | | | | B = | | -40.666667 | + | | 1 | E | + | | | 1 9 | G |
| C = | | 69.333333 | - | | 1 | E | - | | 1 | F | - | | | 5 9 | G |
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Where: E, F, G are arbitrary constants. 解方程组的详细方法请参阅:《多元一次方程组的解法》 |