The new operation "*" is defined as follows: when a ≥ B, a ⁃ B = AB + B, when a ≤ B, a ⁃ B = AB-A, if (2x-1) ⁃ x + 2) = 0, then X=______ ．

The new operation "*" is defined as follows: when a ≥ B, a ⁃ B = AB + B, when a ≤ B, a ⁃ B = AB-A, if (2x-1) ⁃ x + 2) = 0, then X=______ ．

When 2x-1 ≥ x + 2, that is, X ≥ 3, (2x-1) * (x + 2) = (2x-1) (x + 2) + X + 2 = 0, the solution is: x = 0 or x = - 2, ∵ x ≥ 3 ∵ x = 0 or x = - 2 are all rounded off; when 2x-1 ≤ x + 2, that is, X ≤ 3, (2x-1) * (x + 2) = (2x-1) (x + 2) - (2x-1) = 0, the solution is: x = - 1 or x = 12

The new operation "#" is defined as follows: when a ≥ B, a#, B = AB + B, when a #

When (2x-1) ≥ (x + 2), that is, X ≥ 3, (2x-1) # (x + 2) = (2x-1) * (x + 2) + (x + 2) = (x + 2) (2x) = 0, x = 0 or x = - 2, so x has no solution
When (2x-1)

The new operation "*" is defined as follows: when a ≥ B, a ⁃ B = AB + B, when a ≤ B, a ⁃ B = AB-A, if (2x-1) ⁃ x + 2) = 0, then X=______ ．

When 2x-1 ≥ x + 2, that is, X ≥ 3, (2x-1) * (x + 2) = (2x-1) (x + 2) + X + 2 = 0, the solution is: x = 0 or x = - 2, ∵ x ≥ 3 ∵ x = 0 or x = - 2 are all rounded off; when 2x-1 ≤ x + 2, that is, X ≤ 3, (2x-1) * (x + 2) = (2x-1) (x + 2) - (2x-1) = 0, the solution is: x = - 1 or x = 12

The minimum value of the function y = x squared 2 + 4x + 1 is

y=x²+4x+4-4+1
=(x+2)²-3
(x+2)²≥0
(x+2)²-3≥-3
So the minimum is - 3

The coil of a motor has a resistance of 5 ohm. When it works normally in the 220 V lighting circuit, the current is 4a
Question 1: how much work does the motor do in one minute?
2: How many joules of heat does the motor give out in one minute?

t=1min=60s
1.W=UIt=220*4*60=52800J
2.Q=I^2*rt=4*4*5*60=4800J

If n-1 / 3M = 0, then M and N are proportional; if M: 3 = 1 / 3: n, then M and N are proportional

Positive proportion and negative proportion

Connect the microwave oven marked with "220 V, 750 W" to the circuit with 220 V voltage. When it works normally, the current passing through it is______ Ann, its resistance is______ Oh, what's the power consumption of this microwave oven for 2 minutes______ Scorch

"220 V, 750 W" microwave oven means that the rated voltage of microwave oven is 220 V, the rated power is 750 W, the microwave oven works normally, the current is: I = Pu = 750 W, 220 V = 3.41 a, the resistance is: r = u2p = (220 V) 2750 w = 64.5 Ω, w = Pt = 750 W × 120 s = 90000 J

The square of 4x - 4x + 1-4 + 12x-9x, where x = - 1

The first translation is 5x square - 8x + 3 = 0, the cross decomposition is (x-1) (5x-3) = 0, and then substituting into x = - 1, the answer is 16

When an electric appliance is connected to a 36V circuit, the current is 0.5A and the voltage rises to 72V, what is the resistance and current,

U = 36 V, I = 0.5 A, r = u / I = 36 / 0.5 = 18 Ω
When the voltage rises to 72V, what is the resistance and current?
R = 18 Ω, u = 72 V, I = u / r = 72 / 18 = 4 A
When the voltage rises to 72V, the resistance is still 18ohm and the current is 4a

1. The outline of an arch bridge is parabolic (not shown in the figure), with an arch height of 6m and a span of 20m. The distance between two adjacent pillars is 5m
thank you
When the arch bridge is under the ground, there is a 2m wide isolation belt in the middle of the two-way lane. Can one of the lanes drive three cars with 2m wide and 3M high? The gap between cars is not enough to explain your reason!

From the distance of 5 meters, we know that e (5, y) is substituted by y = 4.5 meters, so EF = 10-4.5 = 5.5 meters. 3. In the middle is a 2-meter-wide isolation belt, which is 2 meters wide, with three cars, (7, y) is substituted by y = - (3 / 50) * 7 * 7 + 6 = 3.06 > 3