If x2-2x + 1 = 0, then 2x2-4x=______ .
From x2-2x + 1 = 0, we know that if x2-2x = - 1, then 2x2-4x = 2 (x2-2x) = 2 × (- 1) = - 2
The solution of equation 3x + (X-5) = 2x-13 is
-4
2x-3/4=5/6
.
2X-3/4=5/6
2X=5/6+3/4
2X=19/12
X=19/24
How to solve the equation of 2x + 2x = 30 in Volume I of grade 6
2X + 2x of 3 = 30
8/3x=30
x=30÷8/3
x=45/4
If you don't understand this question, you can ask. If you are satisfied, please click "praise" in the lower right corner
In addition, please send and click my avatar to ask me for help,
RELATED INFORMATIONS
- 1. Junior one math problem, with the equation solution, fill in the blanks, only write the answer! Only write the equation formula! 1. It takes 55 seconds for a bus to cross the 690 meter long bridge and 45 seconds to cross the 490 meter long tunnel at the same speed 2. A city has a population of 4.2 million. In order to control the population growth rate within 1% one year later, a population plan is formulated: the urban population growth rate is controlled at 0.8%, and the rural population is controlled at 1.1%. How many people are the urban population and the rural population in a city? 3. The distance between a and B is 448 km. A local train starts from a and runs 60 km per hour, while an express train starts from a and runs 80 km per hour. How many hours should the local train start to reach B at the same time? 4. The train was blocked on the way for six minutes, and then the speed was increased from 40 km / h to 50 km / h. Q: how many km can we make up for the delay? 5. A clock is 3 minutes slower than the standard time every hour. If it is aligned with the accurate time at 6:30 in the morning, then the clock indicates 12:50 at noon. What is the accurate time?
- 2. 1、 Solve the following equations 1, {x + y = 3, y + Z = 5, x + Z = 4} 2、{x/2=y/3=z/5,2x+y+3z=88} Please, please.
- 3. Given the function f (x) = 3ax + 1-2a, there exists X1 on [- 1,1], such that f (x1) = 0 (x1 is not equal to plus or minus one), then the value range of a is () A.(-1,1/5) B.(1/5,+∞) C.(-∞,-1)∪(1/5,+∞) D.(-∞,-1)
- 4. ① If two of the equations x ^ 2 + 2 (a + 3) x + 2a-3 = 0, one is greater than 3 and the other is less than 3, find the value range of the real number a ② The equation x ^ 2 + X + 1-A = 0 has two real roots with different signs, and the value range of a is obtained I didn't understand how to solve the problem in class
- 5. Some problems of factorization and solving equations Factorization: 1.(2X+1)Yv2+(2X+1)Yv2 2.Xv·4Y-Xv2·Yv3+Xv3·Yv2-X·Yv4 3.2Xvn - 6Xv(n-1)- 8Xv(n-2) 4.(Xv2+Yv2-1)v2 - 4Xv2·Yv2 Solve the inequality 1.2Xv2-3X-2>0 2.-6==0 Solve the equations 1.a.x+y-1 b.2Xv2+3XY+Yv2=5 2.a.x-2y=0 b.3Xv2+2XY=10 This is a senior one's paper, but I didn't go to the connecting class in the summer vacation, so these will not The second question is 2. Xv4 · y-xv2 · yv3 + xv3 · yv2-x · yv4, which means square
- 6. Solving problems by factorization 3x (X-2) = X-2 to find X1 =? X2 =?
- 7. Ask for help in math. About factorization (a+b)2(a-b)+(a-b)2(a+b) (x+y)2-4y2 (m+2n)2+2(m+2n)(2m+n)+(2m+n)2 x2+2xy+y2-4x-4y-5 a4-a2-72 x2-3x3-9+27x
- 8. 3 times the fourth power of x minus the second power of x minus 2
- 9. The monotone decreasing interval of function f (x) = 2 ^ x ^ 2-1 is
- 10. Find the monotone interval of function f (x) = x + 1 / x + 1, and find its maximum and minimum Help!
- 11. 3x + X + 6 = 26, solve the following equation
- 12. If the solution of equation 3x-1 = 5 is the solution of equation m + X / 2 = 6, then M=
- 13. 0.3x + 0.9 = 45.3
- 14. There is a batch of coal in the factory. It is planned to burn 6 tons a day, which can burn 80 days. In fact, it saves 20% every day compared with the original plan. How many days did this batch of coal actually burn?
- 15. A pile of coal, originally planned to burn 3 tons a day, can burn 96 days. In fact, 2.4 tons a day, how many days can actually burn? (answer in proportion)
- 16. A batch of coal was transported to a factory. Originally, it was planned to burn 0.5 tons of coal per day for 30 days. In fact, it burned 10 days more. How many tons per day?
- 17. The canteen transported a batch of coal. Originally, it was planned to burn 0.5 tons of coal every day for 30 days. Actually, it saved 0.05 tons every day. How many days does this batch of coal actually burn
- 18. A pile of coal, the factory originally planned to burn 60 days, 15 tons a day, the actual daily savings of 20% than the original plan, this batch of coal actually burned how many days?
- 19. A batch of coal is transported to a factory. It is planned to burn 5 tons per day for 90 days. How many days can it burn 4.5 tons per day
- 20. 1. A pile of coal, originally planned to use 1.5 tons per day, can use 30 days If 0.25 tons of coal can be saved every day, how many days can this pile of coal be used? 2. On a 1:30000000 map, the distance between Beijing and Guangzhou is 7cm. How many kilometers is the actual distance between Beijing and Guangzhou?