It is known that the largest integer solution of inequality 4 (x-3) + 5 > 8 (x-1) + 7 is the solution of the equation 4x + AX = 4 about X, and the value of a is obtained See clearly, it's >!

4(x-3)+5＞8(x-1)+7
4x-12+5>8x-8+7
4x

8x of 9 / 4 = 2 of 15

8x of 9 / 4 = 2 of 15
2X out of 9 = 2 out of 15
X of 9 = 1 of 15
X = 3 / 5

1) if the quadratic trinomial (M-3) x & # 178; - (M-3) x + 1 is a complete square, the value of M is obtained?
2) to prove that there are two unequal real roots for the quadratic equation of one variable X & # 178; - 4kx + 2K & # 178; - 4k-7 = 0 of X
3) the solution of the equation 4x & # 178; + 2nx + n & # 178; - 2n + 5 = 0 is determined by solving the equation

The first question: let m = 7 let B & # 178; - 4ac = 0
The second question: if delta = 4 (2k & # 178; + 4K + 7) is always greater than 0, there are two unequal real roots
The third question: if there is no real number root, we should use the above formula to get - 8N & # 178; + 3n-80 is always less than 0, that is, there is no real number root
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It is known that the coordinates of the three vertices of △ ABC are a (- 5,0) B (3, - 3) C (0,2), and the linear equations of height on the BC edge are obtained respectively

1. Let the linear equation of BC be y = k 'x + B'
The points B (3, - 3), C (0,2) are substituted into the above functions to form the equations
-3=k‘×3+b’
2=k‘×0+b’
The solution is: K '= - 5 / 3, B' = 2
2. Let the linear equation of high ad on BC be y = KX + B
Then k = - 1 / K & # 39; = - 1 / (- 5 / 3) = 3 / 5 = 0.6
Therefore, the linear equation of ad is y = 0.6x + B
And substituting point a (- 5,0), we get
0=0.6×（-5）+b
So: B = 3
A: the linear equation of high ad on BC side is y = 0.6x + 3

-(- 4.5) △ square of (1 / 2-0.25) - 3.5 △ square of negative 0.25 of absolute value
Should it be 16 or 128,

-(-4.5)/(1/2-0.25)²-3.5/|-0.25|²
=4.5/（1/4）²-3.5/（1/4）²
=（4.5-3.5）/（1/16）
=1×16
=16

Xiaodong uses an energy meter to calculate the hourly electricity consumption of the household electric cooker when cooking and keeping warm
The dial of his home appliance energy meter is marked with "600revs / (kW. H)". Xiaodong connects the electric cooker to the circuit. When cooking, Xiaodong observes through his watch that it takes 6S to turn around the red mark on the edge of the energy meter dial. When keeping warm, it takes 1min to turn around the red mark on the edge of the energy meter dial through his watch
According to the observation data of Xiaodong's experiment, what are the hourly power consumption of Xiaodong's electric cooker when cooking and keeping warm?

60s / 6S = 10 * 60 = 600 cooking at 1 degree per hour is 60 / 600 = 100 / 1000 = 0.1 degree

Given the set a = {x | x2-4x + 3 ＜ 0}, B = {x | 2 ≤ x ≤ 4}. (1) try to define a new operation △ so that a △ B = {1 ＜ x ＜ 2}; (2) calculate B △ a according to the operation in (1)

(1) ∵ a = {x | x2-4x + 3 ＜ 0} = {x | 1 ＜ x ＜ 3}, B = {x | 2 ≤ x ≤ 4}, a △ B = a ∩ (∁ RB) = {x | 1 ＜ x ＜ 2}; (2) according to the Title Meaning: B △ a = B ∩ (∁ RA) = {x | 2 ≤ x ≤ 3}

Is the heat dissipation of refrigerator converting electric energy into heat energy or the heat in refrigerator into the outside?
Refrigerator detailed working principle!

Refrigerator cooling is to transfer the heat inside the refrigerator and the heat of heat generator such as compressor to the outside. The working principle of refrigerator: when Freon is in the gas state, it is pressurized by the compressor. After being pressurized, it flows to the condenser on the back of the refrigerator through the throat. After being cooled by the radiator (the temperature will rise after the material is compressed), it condenses into liquid

Divide 1 / X (x + 1), 1 / (x + 1) (x + 2), 1 / (x + 2) (x + 3) into general parts, and note the simplest common denominator separately

The simplest common denominator is: X (x + 1) (x + 2) (x + 3)
So 1 / X (x + 1), 1 / (x + 1) (x + 2), 1 / (x + 2) (x + 3) are all divided
(x+2)(x+3)/x(x+1)(x+2)(x+3)
x((x+3)/x(x+1)(x+2)(x+3)
x(x+1)/x(x+1)(x+2)(x+3)

In the circuit shown in the figure, L1 and L2 are incandescent bulbs marked with "220V & nbsp; 25W" and "220V & nbsp; 40W" respectively. In order to make L1 and L2 light up, and L1 is brighter than L2, the switch should be closed . when switch When closed, the fuse is blown

① According to the figure, the power supply voltage is 220 V, and the rated voltage of the two bulbs is 220 v. if the two bulbs are connected in parallel, L2 is brighter, which is not in line with the meaning of the problem. Because P = u2r, the resistance of the two bulbs are R1 = u2p1 = (220 V) 225 w = 1936 Ω, R2 = u2p2 = (220 V) 240 w = 1210 Ω. When the two bulbs are connected in series, the formula P = I2R shows that L1 is brighter. Therefore, the switch S1 needs to be closed when the two bulbs are connected in series; ② it is known The rated power of the two bulbs is not large, and the fuse is blown out. It is not caused by excessive power, but by short circuit, that is, switches S1 and S3 are closed at the same time

It is known that the largest integer solution of inequality 4 (x-3) + 5 > 8 (x-1) + 7 is the solution of the equation 4x + AX = 4 about X, and the value of a is obtained See clearly, it's >!