(2x + 1).(3y - 2) = 12
Lập bảng:
2x + 1 | -12 | -6 | -4 | -3 | -2 | -1 | 1 | 2 | 3 | 4 | 6 | 12 |
x | -13/2 | -7/2 | -5/2 | -2 | -3/2 | -1 | 0 | 1/2 | 1 | 3/2 | 5/2 | 11/2 |
3y - 2 | -1 | -2 | -3 | -4 | -6 | -12 | 12 | 6 | 4 | 3 | 2 | 1 |
y | 1/3 | 0 | -1/3 | -2/3 | -4/3 | -10/3 | 14/3 | 8/3 | 2 | 5/3 | 4/3 | 1 |
Vậy...
\(1+2+3+...+x=50\Leftrightarrow\frac{\left(x+1\right).x}{2}=50\Leftrightarrow\left(x+1\right).x=100??\)
1,tự lập bảng rồi tìm
2,\(1+2+3+..+x=50\Leftrightarrow\frac{x\left(x+1\right)}{2}=50\Leftrightarrow x\left(x+1\right)=100\)
sai đề?