Factorization (xsquare-xsquare) - (xsquare-x) - 2

Factorization (xsquare-xsquare) - (xsquare-x) - 2

(xsquare-x) square - (xsquare-x) - 2
=(x²-x-2)(x²-x+1)
=(x-2)(x+1)(x²-x+1)

The solution of equation x squared equal to X

X = 1

The solution of equation 7 / X squared + X + 4 / X squared - x = 6 / X squared is

7/x(x+1)+4/x(x-1)=6/x²
Multiply both sides by x-178; (x + 1) (x-1)
7x²-7x+4x²+4x=6x²-6
5x²-3x+6=0
Obviously, the equation has no solution

Point a is a light installed 25m above the playground. The light shines on the ground in the form of a cone. If the angle between the bus AB and AC of the cone is 60 degrees, the area of the light shining on the ground can be calculated
It's Pythagorean theorem

Let the radius of the bottom of the cone be r and the area of the light on the ground be s
r=25*tan(60'/2)
s=3.14*r^2
Let's calculate the result by ourselves!

When Xiao Fang did her homework carelessly, she regarded 6 in an addend as 0 and 7 in a ten as 1. The result turned out to be 731. Can you get the correct answer?

6-0 = 6, 70-10 = 60731 + 6 + 60 = 797

Fill in 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 to make the equation hold. (each number can only be used once.)
○＋○＝○
○－○＝○
○×○＝○○

In order to speed up the development of the western region, a province in the Western Region decided to build a new expressway. A and B engineering teams contracted the project. If a engineering team constructed alone, it would just be completed on schedule; if B engineering team constructed alone, it would take more than six months to complete. Now, a and B engineering teams jointly constructed for four months, and the rest were constructed by B engineering team alone, How long does it take to build this road?

If the original specified time is x and the total quantity is 1
A 1 / X in one month
1 / (6 + x)
According to the equation:
[1/x+1/(6+x)]×4＋（x-4)/(6+x)=1
Solve this equation: x = 12 (month)

（1）x(1-x）²=64%x
（2）200（1+x）²=1400
（3）x（x-1）=2970

(1) A, when x = 0, the left is equal to the right; B, when x is not equal to 0: (1-x) & sup2; = 64%, x = 20% or x = 120%
(2) If the equation is reduced to (1 + x) & sup2; = 7, then: x = positive and negative root sign 7 - 1
(3) X & sup2; - x = 2970, that is, X & sup2; - x + 0.25 = 2970.25, that is, (x-0.5) & sup2; = 2970.25, the solution is x = 54.5 + 0.5 = 55 or x = - 54.5 + 0.5 = - 54

It is known that the distance between a and B is s kilometers. It takes m hours for Wang Gang to go from a to B, and N hours for Zhao Jun to go from B to a. They set out at the same time and travel in opposite directions. When will they meet?

The velocity of Wang Gang is SM, the velocity of Zhao Jun is Sn, the time of meeting is SSM + Sn = MNM + n

1. After the train speed is increased, it is x km / h, which is y km / h faster than before. If it is known that the distance from a to B is a km, the train will arrive () h earlier than before
2. Self designed questions: self compiled a fractional equation that can be transformed into a linear equation of one variable. The requirements for compiling questions are: ① to connect with real life, and its solution conforms to the reality; ② the fractional equation listed according to the meaning of the questions contains two fractions, without constant term, and the denominator of the fraction contains unknowns, which can be transformed into a linear equation of one variable; ③ the questions are complete and the meaning is clear

1 a/{x-y}-a/x
2. It takes the same time for a truck to travel 25 km and a car to travel 35 km. It is known that the car travels 20 km more per hour than the truck. The speed of the two cars can be calculated
Suppose: the speed of the freight car is x km / h, according to the meaning of the question;
25/x=35/(x+20)
The solution is x = 50, so 20 + x = 70
A: the speed of the truck is 50 km / h, and that of the car is 70 km / h