The common factor of 1, single item-5x2yz,15xxyz2 is.
2,,, The simplest common denominator is.
3. When x=, the value of the score is zero.
4. in V=V0+at, if v, V0, a and a≠0 are known, then t=
5. If x2+ax-b= (x+ 1) (x-2), then a=, b=.
6. If a+b=0, polynomial a3 +a2b+ab2+b3=.
7. Calculate12a2b-3÷ (2a-1B2C) 3 =.
8. Fill in the appropriate algebraic expression in brackets to make it hold.
9. Decomposition factor: A2-4+AB-2B =.
10, when 0 < x < 2, simplify+=.
1 1, given that x=0 is a solution of equation =, then a=.
12. When someone hits the target, he hits the target A ring m times each time and the target B ring n times each time, then the average number of rings hit each time is.
Second, multiple-choice questions (3 points for each question, *** 18 points)
13, the following factorization result is correct ()
a、x2-5x-6 =(x-2)(x-3)b . 2 x2+2x = x(2x+2)
C.a3-a2+a=a(a2-a) D.xy-2x = x(y-2)
14. If x in the score is enlarged by 2 times and the value of y is reduced to half of the original value, then the value of the score ().
A, unchanged b, expanded by 2 times c, expanded by 4 times d, which is half of the original.
15, if -= 3, the value of is ()
A.b .-c . d-
16. Among the following factorizations, ① 4x2x2+24xy2+36y2 = (2xy+6y) 2,
②3x-3xy+xy2 = 3x( 1-y+y2)③n(m-n)2-m(n-m)2 =(n-m)3，
④ A4-B4 = (A2+B2) (A2-B2), where () can be further decomposed.
a，4 B，3 C，2 D， 1
17, polynomial 4x2+ 1 and a monomial make it a completely flat algebraic expression, then such a monomial has ().
a，5 B，4 C，3 D，2
18 The following algebraic transformation is correct ()
A.= B. x÷x- 1 = 1 C. = D. =2
Third, the calculation problem (7 points for each small question, *** 14 points)
19 、- = 1 20、⊙(x+ 1)
Four, answer questions (8 points for each question, ***24 points)
2 1, known as | x-3y- 1 |+x2-4xy+4y2 = 0, find the value of x+y.
22. Simplify before evaluating.
(-)-a-b, where a = 2 and b =
23. It is known that the quadratic trinomial x2+mx-12 about x can be decomposed into the product form of the first factor of two integral coefficients, and all the values can be found and decomposed into factors.
Verb (abbreviation of verb) 24. The following equation x2+2ax-3a2 = 0 can be solved by factorization. That is, (x-a) (x+3a) = 0, so x 1 = a, x2 = -3a Solve the following equations in a similar way, record the roots of the equations, fill in the table below, and calculate the values of x 1+x2, x 1 x2.
Square path
Solution of the equation
x 1+x2
x 1 x2
x2+3x-4=0
x2-5x-24=0
x2+7x+ 12=0
x2- 1 1x+30=0
Can we draw the conclusion that the sum and product of two x 1 of equation x2+px+q=0 is regular? (9 points)
25, using-= calculation (9 points)
+ +……+
26. The time required for a ship to sail against the current is 1.5 times as long as it needs to sail against the current. There are two ships today, starting from Pier A and Pier B at the same time, face to face. After three hours of meeting, if the two ships are at the same speed in still water, how many hours will it take for the two ships to travel upstream and upstream?
(2) What is the ratio of current velocity to ship speed in still water?
(3) How many hours does it take a ship to get from A to B in still water? (10)