解方程组:{3分之2(m-n)-4分之m+n=-1,6(m+n)-4(2m-n)=16解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16不是(m+n)/2-(m-n)/3=1 (m+n)/3-(m-n)/4=-1 你看清楚,是:解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16
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![解方程组:{3分之2(m-n)-4分之m+n=-1,6(m+n)-4(2m-n)=16解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16不是(m+n)/2-(m-n)/3=1 (m+n)/3-(m-n)/4=-1 你看清楚,是:解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16](/uploads/image/z/5244598-46-8.jpg?t=%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84%3A%7B3%E5%88%86%E4%B9%8B2%28m-n%29-4%E5%88%86%E4%B9%8Bm%2Bn%3D-1%2C6%28m%2Bn%29-4%282m-n%29%3D16%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84%3A%7B%5B2%28m-n%29%2F3-%28m%2Bn%29%2F4%3D-1%2C6%28m%2Bn%29-4%282m-n%29%3D16%E4%B8%8D%E6%98%AF%28m%2Bn%29%2F2-%28m-n%29%2F3%3D1+%28m%2Bn%29%2F3-%28m-n%29%2F4%3D-1+%E4%BD%A0%E7%9C%8B%E6%B8%85%E6%A5%9A%EF%BC%8C%E6%98%AF%EF%BC%9A%E8%A7%A3%E6%96%B9%E7%A8%8B%E7%BB%84%3A%7B%5B2%28m-n%29%2F3-%28m%2Bn%29%2F4%3D-1%2C6%28m%2Bn%29-4%282m-n%29%3D16)
解方程组:{3分之2(m-n)-4分之m+n=-1,6(m+n)-4(2m-n)=16解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16不是(m+n)/2-(m-n)/3=1 (m+n)/3-(m-n)/4=-1 你看清楚,是:解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16
解方程组:{3分之2(m-n)-4分之m+n=-1,6(m+n)-4(2m-n)=16
解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16
不是(m+n)/2-(m-n)/3=1
(m+n)/3-(m-n)/4=-1 你看清楚,是:解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16
解方程组:{3分之2(m-n)-4分之m+n=-1,6(m+n)-4(2m-n)=16解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16不是(m+n)/2-(m-n)/3=1 (m+n)/3-(m-n)/4=-1 你看清楚,是:解方程组:{[2(m-n)/3-(m+n)/4=-1,6(m+n)-4(2m-n)=16
(m+n)/2-(m-n)/3=1
(m+n)/3-(m-n)/4=-1
整理得:
m/6+5n/6=1 (1)
m/12+7n/12=-1 (2)
(1)-2*(2):
-n/3=3
解得:n=-9
代入(1):m=51
1/2(m-n) + 1/4(m+n) + m + n/3 - m - n/6
= 1/2m - 1/2n + 1/4m + 1/4n + m + n/3 - m - n/6
=(1/2m + 1/4m + m - m) + [(-1/2n + 1/4n) +( n/3 - n/6)]
= 3/4m + (-1/4n + 1/6n)
= 3/4m -1/12n
把m=-9 n=-3代入1/2(m-n)+1/4(m+n)+m+n/3-m-n/6可得
1/2[ -9 -(-3)] + 1/4(-9-3)+(-9)-3/3 -(-9)-(-3/6)
= 3/4m -1/12n
= 3/4 * (-9) - 1/12 * (-3)
= -27/4 + 1/4
= -26/4
= -13/2
1/2(2x的2次方-6x-4)-4(-1+x+1/4x的2次方)
= 1/2(2x^2 - 6x - 4) - 4(-1 + x + 1/4x^2)
= 1/2 * 2x^2 - 1/2 * 6x - 1/2 * 4 - 4 * (-1) - 4 * x - 4 * 1/4x^2
= x^2 - 3x - 2 + 4 - 4x - x^2
= (x^2 - x^2) + (- 3x - 4x)- 2 + 4
= -7x + 2
把 x = 5 代入上式可得
1/2(2x的2次方-6x-4)-4(-1+x+1/4x的2次方)
= -7x + 2
= -7 * 5 + 2
= -33