The equation x ^ 2-2mx + 2m ^ 2-1 = 0 of X has at least one negative real root, and the range of M is obtained

The equation x ^ 2-2mx + 2m ^ 2-1 = 0 of X has at least one negative real root, and the range of M is obtained

In the first case, there is only one real root discriminant: (2m) ^ 2-4 * (2m ^ 2-1) = 0, M = 1 or - 1. When m = 1, x = 1 does not match. When m = - 1, x = - 1 matches. Therefore, in the first case, M = - 1. In the second case, there are two positive and negative discriminant: - 4m ^ 2-4 > 0, which are different: X1 * x2 = 2m ^ 2-1

The first degree equation of three variables: ① x + y + Z = 2 ② 2x-y + 3Z = 13 ③ 3x + 2y-z = - 4
Please try your best to write down the process of calculation!

① + 2, 3x + 4Z = 15, 4
① * 2 - 3, get - x + 3Z = 6 5
LIANLI 4.5 finding x, Z substituting for y '
What you want is the process``
I didn't give you the result

The mathematics problem of one variable linear equation in the second semester of grade seven is 1 / 3x-1-2x = - 1

1/3x-1-2x=-1
1/3x-2x=-1+1
x(1/3-2)=0
x=0

2x-1 of 5 + 3y-2 of 4 = 2, 3x of 3 + 3Y of 1-4 = 4 of 3

（2x-1)/5+(3y-2)/4=2
(3x + 1) / 3 - (3Y + 2) / 4 = 4 / 3, i.e
8x-4+15y-10=40
12x + 4 - (9y + 6) = 16, i.e
8x+15y=54
4x-3y = 6, i.e
x=3
y=2