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二元一次方程组、、、快!急用--

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二元一次方程组、、、快!急用--
用代入法解下列方程组:【记住、是用 代入法!】
3x+4y=16 4(x-y-1)=3(1-y)-2 2x-3y=4
5x-6y=33 x/2 + y/3=2 1/2y -x=-1
由11x-9y=6用含x的整式表示y得y= ,用含y的整式表示x得x= .
..你会答的都写上、、答好我一定加分!
3x + 4y = 16 (1)
5x - 6y = 33 (2)
(1)x3
9x + 12y = 48 (3)
(2)x2
10x - 12y = 66 (4)
(3)+(4)
19x = 114
x = 6
y = -1/2
4(x-y-1) = 3(1-y)-2
4x - 4y - 4 = 3 - 3y -2
4x - y = 5 (1)
x/2 + y/3 = 2
3x + 2y = 12 (2)
(1)x2
8x - 2y = 10 (3)
(2)+(3)
11x = 22
x = 2
y = 3
2x - 3y = 4 (1)
1/(2y - x) = -1
x - 2y = 1 (2)
(2) x 2
2x - 4y = 2 (3)
(1)-(3)
y = 2
x = 5
11x - 9y = 6
11x = 6 + 9y
x = [3( 2+3y )]/11
11x - 9y = 6
11x - 6 = 9y
y = (11x - 6)/9