If the polynomial 2x4 + x3-ax2 + BX + A + B-1 has two factors x + 3, X-2, then a = B=

If the polynomial 2x4 + x3-ax2 + BX + A + B-1 has two factors x + 3, X-2, then a = B=

Let 2x4 + x3-ax2 + BX + A + B-1 = 2 (x + 3) (X-2) P (x),
Let x = - 3, then - 8a-2b + 134 = 0,
Let x = 2, then - 3A + 3B + 39 = 0,
The solution is a = 16, B = 3

If X3 + AX2 + BX + 8 has two factors x + 1 and X + 2, then a + B = ()
A. 7B. 8C. 15D. 2l

Let X3 + AX2 + BX + 8 = (x + 1) (x + 2) (x + C) = X3 + (3 + C) x2 + (2 + 3C) x + 2c, ∧ C = 4, so a = 7, B = 14, ∧ a + B = 21, so D

If the fifth power of polynomial X - (A-2) the third power of X + (B + 3) X-1 does not contain X & # 179; and X terms, find the value of a and B

Y (x) = x ^ 5 - (A-2) x ^ 3 + (B + 3) X-1 does not contain: x ^ 3, X items,
Then the coefficients of x ^ 3 and X are both 0
a - 2 = 0
b + 3 = 0
Thus: a = 2, B = - 3

If the real numbers x and y satisfy (1 + I) (x + Yi) = (1-I) (2 + 3I), try to judge the quadrant of point P (x, y)

Left and right,
X-Y + (x + y) I = 5 + I, so,
x－y＝5,x＋y＝1,
X = 3, y = - 2, P in the fourth quadrant

It is known that the warehouse a can transfer 110 tons of cement, the warehouse B can transfer 80 tons of cement, and the warehouse a needs 70 tons of cement
① Suppose x (tons) of cement transported from warehouse B to place a, and find the function of total freight y (yuan) with respect to X (tons);
② How many tons of cement will be transported to a and B from warehouse A and B respectively? What is the most economical freight?

Methods: (1) set up a warehouse to transport x tons of cement to a warehouse. According to the meaning of the title, y = 12 × 20x + 10 × 25 (100-x) + 12 × 15 × (70-x) + 8 × 20

Given Tana = 1 / 2, find the value of (sin2a-2) / (1 + (COSA) ^ 2) on line

sina/cosa=tana=1/2
cosa=2sina
Substituting Sin & sup2; a + cos & sup2; a = 1
So Sin & sup2; a = 1 / 5
cos²a=4/5
sin2a=2sinacosa
=2sina(2sina)
=4sin²a
=4/5
So the original formula = (4 / 5-2) / (1 + 4 / 5) = - 2 / 3

The distance between the two trains is 40% of the total length of the railway between the two cities after running for 2.4 hours. It is known that the speed of train a is 20% faster than that of train B. train B runs 45 kilometers per hour. How many kilometers is the total length of the railway between the two cities?

[45 + 45 × (1 + 20%)] × 2.4 ^ (1-40%), = (45 + 45 × 120%) × 2.4 ^ 60%, = (45 + 54) × 2.4 ^ 60%, = 99 × 2.4 ^ 60%, = 396 (km); a: the whole journey is 396 km

If the function y = (m − 3) XM2 − 7 is a quadratic function, then the value of M is______ ．

If y = (M-3) xm2-7 is a quadratic function, then M2-7 = 2, and M-3 ≠ 0, so (M-3) (M + 3) = 0, m ≠ 3, the solution is: M1 = 3 (not suitable for the problem), M2 = - 3, M = - 3. So the answer is: - 3

The speed of the moped is 36 km in 2 hours, and the aircraft can fly 1200 m in 2 seconds. Then the ratio of the speed of the moped to that of the aircraft is ()

The car is 18 km / h, and the plane is 1200 / 2 * 3600 = 2160 km / h. therefore, the ratio is 18:2160 = 1:120
The plane is supersonic

Given x, y ∈ (0, + ∞), and 2x + 3Y = 3, find the minimum value of 1 / 2x + 1 + 1 / y + 2
Find the minimum value of 1 / (2x + 1) + 1 / (y + 2)

For convenience, let 2x + 1 = a, y + 2 = B  a + 3B = 2x + 1 + 3Y + 6 = 2x + 3Y + 7 = 10 1 / (2x + 1) + 1 / (y + 2) = 1 / A + 1 / b = (1 / A + 1 / b) (a + 3b) / 10 = (1 + A / B + 3B / A + 3) / 10 ≥ (1 + 2 √ 3 + 3) / 10 = (2 + √ 3) / 5 if and only if a / b = 3B / A, the equal sign holds 1 / (2x + 1) + 1 / (y + 2)