1.8-8x/1.2 - 1.3-3x = 5x-0.4/0.

1.8-8x/1.2 - 1.3-3x = 5x-0.4/0.

(1.8-8x) / 1.2 - (1.3-3x) / 2 = (5x-0.4) / 0.3 (remove brackets) = > 1.8 / 1.2-8x / 1.2 - 1.3 / 2 + 3x / 2 = 5x / 0.3 - 0.4 / 0.3 = > 3 / 2 - 2x / 0.3 - 1.3 / 2 + 3x / 2 = 5x / 0.3 - 4 / 3 (x term moves to one side, others to the other side of the equation) = > 5x / 0.3 + 2x / 0.3-3x / 2 = 4 / 3 + 3 / 2

-3x ^ 2-2x + 8 greater than or equal to 0

[-2,4/3]
That is, 3x ^ 2 + 2x-8 is less than or equal to 0
(3x-4) * (x + 2) less than or equal to 0
-2 less than or equal to x less than or equal to 4 / 3

Using Laplace transform to solve ordinary differential equation: y '' '- 3Y' '+ 3Y' - y = - 1, y '' (0) = y '(0) = 1, y (0) = 2
2. Using Laplace transform to solve the ordinary differential equation y '' '+ y' = e ^ 2T satisfying the initial condition y (0) = y '(0) = y' '(0) = 0
Thank you very much

Let y = e ^ Rx
The characteristic equation is obtained
r^3-3r^3+3r-1=0
R has triple real roots r = 1
So y = e ^ x (C1 + c2x + C3x ^ 2)
The boundary condition is y = e ^ x (2-x + 1 / 2x ^ 2)

Given that x2 + y2 = 25, x + y = 7, and x > y, find X-Y

∵ x + y = 7, ∵ (x + y) 2 = 49, that is, X2 + Y2 + 2XY = 49, while x2 + y2 = 25, ∵ 2XY = 49-25 = 24, ∵ X-Y) 2 = x2 + y2-2xy = 25-24 = 1, ∵ X-Y = ± 1, ∵ x > y, ∵ X-Y = 1

1435 divided by 35 vertical plus checking calculation

Given the set (A1, A2, A3,. An) and constant A0, definition: w = cos ^ 2 (a1-a0) + cos ^ 2 (a2-a0). + cos ^ 2 (an-a0) / n
Is the cosine variance of the set (A1, A2, A3,... An) relative to A0. Is the cosine variance of the set (π / 2, 5 π / 6, 7 π / 6) relative to the constant A0 changing with A0

w=[cos^2（π/2-a0）+cos^2（5π/6-a0)+cos^2(7π/6-a0)]/3=[cos（π-2a0）+cos(5π/3-2a0)+cos(7π/3-2a0)+3]/6=[cos(5π/3-2a0)+2cos(5π/3-2a0)cos2π/3+3]/6 …………………… Sum difference product = [cos (5 π / 3-2a0) - cos (5 π /

Solving equation 3 / 4x-16.8 = 20.67 / 8x-0.87 = 16.93 △ 2x = 6.2 (1 / 2-5 / 11) * (5 / 9 * 2 / 3) 8.6-3 / 4x = 2.7

3 △ 2x = 6.2 (1 / 2-5 / 11) * (5 / 9 * 2 / 3) these two questions are not connected, but scattered

A barrel of oil weighs 15.4 kg. After half of the oil is poured out, the barrel weighs 8.6 kg. How many kg?

15.4 - (15.4-8.6) × 2, = 15.4-6.8 × 2, = 15.4-13.6, = 1.8 (kg), answer: the barrel weight is 1.8 kg

Continuity and differentiability of function f (x) = 1-x ^ 2, x = 0 at point x = 0

The left limit of F (x) at x = 0 is 1, and the right limit is - 1, so it is discontinuous and non differentiable at 0

On the comma expression: (a = 3, B = 5, B + = a, C = 5 * B, d = 6) the final result is the result. Is the final value 6

Comma operator has the lowest priority. It connects the two expressions. For example: (3 + 5,6 + 8) is called comma expression. Its solving process starts with expression 1 and then expression 2. The whole expression value is the value of expression 2. For example, (3 + 5,6 + 8) has the value of 14 (a = 3 * 5, a * 4) has the value of 60