Given 3x + y + 2Z = 28,5x-3y + Z = 7, find the value of X + y + Z

Given 3x + y + 2Z = 28,5x-3y + Z = 7, find the value of X + y + Z

After very careful observation, it is found that:
x+y+z=4/7(3x+y+2z)-1/7(5x-3y+z)
=15

X ratio 2 = 3 to 5 24% to 8 / 25 = 1.2 x 7x + 42-3x = 166
fast

x=3/5*2=6/5
0.24*1.2=8x/25 x=0.9
4x=166-42 x=31

X-0.25=1/4 X/4=30% 4+0.7X=102 2/3X+1/2X=42

X=0.5 X=1.2 .

If the equation (K + 2) x2 + 4kx-5k = 0 about X is a linear equation of one variable, then K=______ The solution X of the equation=______ ．

According to the characteristics of one variable linear equation, we get K + 2 = 0, and the solution is k = - 2. Therefore, the original equation can be reduced to - 8x + 10 = 0, and the solution is x = 54

We know the equation 2x & # 178; + (K & # 178; + K-6) x + 2K about X. if its two numbers are opposite to each other, then K=____ This is the topic. I'm looking forward to Xueba. Thank you very much

According to the relation between root and coefficient - (K & # 178; + K-6) / 2 = Xi + x2 = 0
Then K & # 178; + K-6 = 0
The solution is k = 2 or K = - 3
The two solutions are brought into the equation to verify that only - 3 satisfies,
So k = - 3

We know the equation 2x & # 178; + (K & # 178; + K-6) x + 2K = 0 about X. if its two numbers are opposite to each other, then k =?

If the sum of two is 0, that is - (K & # 178; + K-6) / 2 = 0, the solution is k = - 3 or 2
When k = 2 △ = - 32 ＜ 0, the equation has no solution, and when k = - 3 △ = 48 ＞ 0
So k = - 3

When k takes what value, the two equations 2x & # 178; + (K & # 178; - 2k-15) x + k = 0 are opposite to each other

Solution: sum of two = - (k ^ 2-2k-15) = 0, K1 = 5, K2 = - 3,
x^2=-k／2,
k

When k is what value, the two equations 2x & # 178; + X (K & # 178; - 2k-15) + k = 0 are opposite to each other
Where - (K & # 178; - 2k-15) / 4 = 0 is obtained,

The two roots of the equation 2x & # 178; + X (K & # 178; - 2k-15) + k = 0 are: X1 = [- B + √ (B & # 178; - 4ac)] / 2ax2 = [- B - √ (B & # 178; - 4ac)] / 2a, which are opposite to each other, then X1 = - x2 ■ [- B + √ (B & # 178; - 4ac)] / 2A = - [- B - √ (B & # 178; - 4ac)] / 2A = [B + √ (B & # 178; - 4ac)] / 2A ■ -

If 5x-2 and 9 + 2x are opposite numbers, then X-2 =?

5x-2+9+2x=0
x=-1
x-2=-3

In the bivariate linear equation 2x + 3Y = 6, X and y are opposite numbers, x = ---, y=---

If we change x to - y, we have 2 * (- y) + 3Y = 6, x = - 6, y = 6
For the best