Under the teacher's education, I corrected my learning attitude and method

Under the teacher's education, I corrected my learning attitude and method

Correct learning attitude
Correct learning methods
The method cannot be "correct"

After the teacher's education, Xiao Ming corrected his learning attitude and purpose

After the teacher's education, Xiaoming students correct the learning attitude, clear learning purpose
Hope to help the landlord~

Under the teacher's education, he made clear his learning attitude and purpose

Under the teacher's education, he corrected his learning attitude and clarified his learning purpose

Subtract a number from the numerator of 1993 / 1992, add this number to the denominator, and the score is two-thirds
I know the formula, but the formula with explanation. 3Q

Let this number be X
Then (1992-x) / (1993 + x) = 3 / 2
De denominator, 2 (1992-x) = 3 (1993 + x)
Remove brackets, 3984-2x = 5979 + 3x
Transfer items and merge similar items, 5x = - 1995
x=-399
If you understand, please take it

Given that the function e ^ 2x + (x + 1) e ^ x is a special solution of the second order linear non-homogeneous differential equation y "+ ay '+ by = CE ^ x with constant coefficients, the general solution of the differential equation is
I don't know how to get C1E ^ 2x + c2e ^ x + Xe ^ X. please forgive me for the small score!

Y = e ^ 2x + (x + 1) e ^ XY '= 2E ^ 2x + e ^ x + Xe ^ XY "= 4E ^ 2x + 3E ^ x + Xe ^ x is brought into y' '+ ay' + by = CE ^ x solution, a = - 3B = 2 C = 2Y '' - 3Y '+ 2Y = 2E ^ X3 ^ 2-4 * 2 = 1 > 0 in 1 = 2 in 2 = 1 general solution y = C1E ^ 2x + c2e ^ x special solution e ^ 2x + (x + 1) e ^ x solution is y = C1E ^ 2x + c2e ^ x + Xe ^ X

Known: M & # 178; = n-2, n & # 178; = m-2, find M & # 179; - 2Mn + n & # 179;

m²=n-2…… ①
n²=m-2…… ②
① - 2: M & # 178; - N & # 178; = N-M
It is reduced to: (M + n) (m-n) = - (m-n)
That is m + n = - 1
m³ -2mn+n³
Original formula = m (n-2) - 2Mn + n (m-2)
=mn-2m-2mn+mn-2n
=-2m-2n
=-2(m+n)
=2

56 rational number addition, subtraction, multiplication, no division, simple operation,
Must not appear division, the problem is difficult, the best is the fraction and decimal

1. 6 - (- 6) = 122, 0-9 = - 93, 0.8 - (- 0.8) = 1.64, 45 + (- 49) = - 45, - 11-10 = - 216, 10 - (- 7) = 177, 9.1-2.3 = 6.88, 5.3 - (- 2.4) = 7.79, 0.5 - (- 0.5) = 110, - 47-12 = - 5911, 0.3-1 / 2 = - 0.212, 7-1 / 6 = 6 and 5 / 613, - 8.6 - (- 7.8) =

In the space coordinate system, we know that the three vertices of the right triangle ABC are a (- 3, - 2,1), B (- 1, - 1, - 1), C (- 5, x, 0), then the value of X is______ ．

∵ a (- 3, - 2,1), B (- 1, - 1, - 1), C (- 5, x, 0), ∵ AB = (2,1, - 2), BC = (- 4, x + 1,1), AC = (- 2, x + 2, - 1) can be divided into three cases: ① A is right angle, ab · AC = 0, ∵ 4 + X + 2 + 2 = 0, ∵ x = 0; ② B is right angle, ab · BC = 0, ∵ 8 + X + 1-2 = 0,