Given that x = - 1 is a root of the equation 2x2 + ax-a2 = 0 about X, then a=______ The other one is______ ．

Given that x = - 1 is a root of the equation 2x2 + ax-a2 = 0 about X, then a=______ The other one is______ ．

According to the meaning: 2-a-a2 = 0, solution: a = - 2 or 1, when a = - 2, then 2x2 + ax-a2 = 0 is: 2x2-2x-4 = 0, sorting out: x2-x-2 = 0, (x + 1) (X-2) = 0, solution: X1 = - 1, X2 = 2, another root is: 2, when a = 1, then 2x2 + ax-a2 = 0 is: 2x2 + X-1 = 0, (x + 1) (X-12) = 0, solution

It is known that x = - 2 is a root of the equation 2x2 + ax - A2 = 0 about X, and the value of a is obtained

When x = - 2, 8-2a-a2 = 0, that is: A2 + 2a-8 = 0, (a + 4) (A-2) = 0, the solution is: A1 = 2, A2 = - 4

Is the solution of the equation 3x + 2.1 * 4 = 8.4 correct

Yes, substitute x = 0 in the equation, left = right
3x+2.1*4=8.4
3x+8.4=8.4
3x=0
x=0

The solution set of square-3x + 2 ＜ 0 of X

The square of X - 3x + 2 < 0
（x-1）（x-2）

Given that three planes α, β and γ intersect each other, ABC is three intersecting lines. If a / / B, try to prove that the three lines of ABC are parallel to each other

Let a be the intersection of plane α and plane β, B be the intersection of plane β and plane γ, and C be the intersection of plane γ and plane α. If a / / B, then a does not belong to plane γ, that is, a / / plane γ. Because if a does not / / plane γ, then a must intersect plane γ. If the intersection is m, then because straight line a is in plane α and plane β, point m

What's the difference between water vapor in the sky, snow or ice
The higher the temperature is, the lower the temperature is. Why does the water vapor in the air not gradually form water and then ice, but snow

Because of the rapid cooling, water vapor directly condenses into snow instead of liquefying into water and then condensing into ice

F = ma what does f stand for? What does Ma stand for

F is the resultant force on the object, in cattle
M is the mass of the object, in kilogram
A is the acceleration of the object, in meters per square second

Proof: inequality logn (n-1) * logn (n-1) < 1 (n > 1)
The N after log is the base

logn(n-1)*logn(n+1)=(lg(n-1)/lg(n))*(lg(n+1)/lg(n))
Because LG (n-1) n + 1 > 1
So LG (square of n) > LG (n + 1) is 2lgn > LG (n + 1)
So (LG (n + 1) / LG (n))

1/2+1/3+2/3+1/4+2/4+3/4+1/5+2/5+3/5+4/5.+1/40+2/40+.+38/40+39/40=

Group: (1 / 2) + (1 / 3 + 2 / 3) + (1 / 4 + 2 / 4 + 3 / 4) +... + (1 / 40 + 2 / 40 +... + 39 / 40) for the n-th group, the denominator is n, and the molecules are 1 to n-1, with n-1 items in total. The sum of n-th group is an = (1 + 2 +... + n-1) / N = n (n-1) / (2n) = (n-1) / 2 = n / 2-1 / 21 / 2 + 1 / 3 + 2 / 3 + 1 / 4 + 2 / 4 + 3 / 4 + 3 / 5 + 2 / 5

If the sum of three consecutive even numbers is 30, then the three even numbers are______ ．

The one in the middle is x, so the other two are (X-2), (x + 2) and (X-2), (x + 2) according to the theme (X-2) + (x + (x + 2) according to the (X-2) + (x + (x + 2) = 30, 30, and the & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; one in the middle is x, so the other two are (X-2) and the other two are (X-2), (x + 2), according to the theme (X-2 (X-2 (X-2) + (x + (x + X + 2) (x + 2) = 30, 30, 30, 30, and & amp & nbsp; & & nbsp; & nbsp; & & nbsp; & nbsp; & & nbsp; & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & nbsp; & & nbsp; & & nbsp; & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & & nbsp; & nbsp& nbsp; &If x = 10, then the three even numbers are 8, 10 and 12