1.已知3x=4+m,2y-m=5,用含x的代数式表示y为___.2.关于x,y的方程y=kx+b中,当x=2时y=-1,当x=-1时y=5,k=?b=?3.已知|x+2y|+(x-y+1)²=0,则(x+y)²=4.若方程组4x+3y=21,4kx+(k-1)y=4的解互为相反数,则k=5.若方程组ax-by=4,2
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![1.已知3x=4+m,2y-m=5,用含x的代数式表示y为___.2.关于x,y的方程y=kx+b中,当x=2时y=-1,当x=-1时y=5,k=?b=?3.已知|x+2y|+(x-y+1)²=0,则(x+y)²=4.若方程组4x+3y=21,4kx+(k-1)y=4的解互为相反数,则k=5.若方程组ax-by=4,2](/uploads/image/z/6942461-5-1.jpg?t=1.%E5%B7%B2%E7%9F%A53x%3D4%2Bm%2C2y-m%3D5%2C%E7%94%A8%E5%90%ABx%E7%9A%84%E4%BB%A3%E6%95%B0%E5%BC%8F%E8%A1%A8%E7%A4%BAy%E4%B8%BA___.2.%E5%85%B3%E4%BA%8Ex%2Cy%E7%9A%84%E6%96%B9%E7%A8%8By%3Dkx%2Bb%E4%B8%AD%2C%E5%BD%93x%3D2%E6%97%B6y%3D-1%2C%E5%BD%93x%3D-1%E6%97%B6y%3D5%2Ck%3D%3Fb%3D%3F3.%E5%B7%B2%E7%9F%A5%7Cx%2B2y%7C%2B%28x-y%2B1%29%26sup2%3B%3D0%2C%E5%88%99%28x%2By%29%26sup2%3B%3D4.%E8%8B%A5%E6%96%B9%E7%A8%8B%E7%BB%844x%2B3y%3D21%2C4kx%2B%28k-1%29y%3D4%E7%9A%84%E8%A7%A3%E4%BA%92%E4%B8%BA%E7%9B%B8%E5%8F%8D%E6%95%B0%2C%E5%88%99k%3D5.%E8%8B%A5%E6%96%B9%E7%A8%8B%E7%BB%84ax-by%3D4%2C2)
1.已知3x=4+m,2y-m=5,用含x的代数式表示y为___.2.关于x,y的方程y=kx+b中,当x=2时y=-1,当x=-1时y=5,k=?b=?3.已知|x+2y|+(x-y+1)²=0,则(x+y)²=4.若方程组4x+3y=21,4kx+(k-1)y=4的解互为相反数,则k=5.若方程组ax-by=4,2
1.已知3x=4+m,2y-m=5,用含x的代数式表示y为___.
2.关于x,y的方程y=kx+b中,当x=2时y=-1,当x=-1时y=5,k=?b=?
3.已知|x+2y|+(x-y+1)²=0,则(x+y)²=
4.若方程组4x+3y=21,4kx+(k-1)y=4的解互为相反数,则k=
5.若方程组ax-by=4,2x+3y=4与方程组ax+by=2,4x-3y=-10的解相同,求a,b[写过程]
1-4题过程可写可不写,但是最好写下来,
1.已知3x=4+m,2y-m=5,用含x的代数式表示y为___.2.关于x,y的方程y=kx+b中,当x=2时y=-1,当x=-1时y=5,k=?b=?3.已知|x+2y|+(x-y+1)²=0,则(x+y)²=4.若方程组4x+3y=21,4kx+(k-1)y=4的解互为相反数,则k=5.若方程组ax-by=4,2
1.
3x=4+m
m=3x-4
2y-m=5
2y-(3x-4)=5
2y-3x+4=5
2y-3x=1
2y=1+3x
y=(1+3x)/2
2.
y=kx+b中,当x=2时y=-1,当x=-1时y=5
2k+b=-1
-k+b=5
k=-2
b=3
3.
|x+2y|+(x-y+1)²=0
x+2y=0
x-y+1=0
x+2y=0
x-y=-1
x=-1/3
y=2/3
(x+y)²=(-1/3+2/3)²=(1/3)²=1/9
4.
4x+3y=21
4kx+(k-1)y=4
解互为相反数
x+y=0
4x+3y=21
x=21
y=-21
4kx+(k-1)y=4
84k-21(k-1)=4
84k-21k+21=4
63k=-17
k=-17/63
5.
ax-by=4
2x+3y=4
ax+by=2
4x-3y=-10
2x+3y=4
4x-3y=-10
x=-1
y=2
ax-by=4
ax+by=2
-a-2b=4
-a+2b=2
a=-3
b=-1/2
1.3x+1\2=y