S2 Maths (15 points )

2013-03-29 12:45 am

Linear Equation in Two Unknowns

Solve the equations by the method of elimination

y = 1 + 6x = 7x - y -1 = 0

要詳細和有步驟

回答 (2)

2013-03-29 1:39 am

✔ 最佳答案

y = 1+6x ......(1)
7x-y-1 = 0 ......(2)

把(1)代入(2)，可得:
7x-(1+6x)-1 = 0
7x-1-6x-1 = 0
x-2 = 0
x = 2

把 x = 2 代入(1)，可得:
y = 1+6(2)
y = 1+12
y = 13

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2013-03-29 1:05 am

y = 1 + 6x ---> (1)
7x - y -1 = 0 ---> (2)

(1)+(2)

7x -1 = 1 + 6x
x = 2
Sub x = 2 into (1),
y = 1 + 6(2) = 13

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