Rút gọn biểu thức :
a) \(3x\left(x-2\right)-5x\left(1-x\right)-8\left(x^2-2\right)\)
b) \(\left(4x^2-3y\right).2y-\left(3x^2-4y\right).3y\)
c) \(3y^2\left[\left(2y-1\right)+y+1\right]-y\left(1-y-y^2\right)+y\)
mình cần gấp ạ bạn naok tl nhanh mình tick luôn nhé
Cho x,,y ϵ Z, chứng minh rằng :
a,Nếu A = 5x+y ⋮ 19 thì B = 4x-3y ⋮ 19 .
b,Nếu C = 4x+3y ⋮13 thì D= 7x+2y ⋮ 13
1.tìm x
a) \(\left(8-5x\right)\left(x+2\right)+4\left(x-2\right)\left(x+1\right)+2\left(x-2\right)\left(x+2\right)\)
b) \(4\left(x-1\right)\left(x+5\right)-\left(x+2\right)\left(x+5\right)=3\left(x-1\right)\left(x+2\right)\)
2. CMR
a) \(\left(x-y\right)\left(x^4+x^3y+x^2y^2+xy^3+y^4\right)=x^5-y^5\)
b)\(\left(x+y\right)\left(x^4-x^3y+x^2y^2-xy^3+y^4\right)=x^5+y^5\)
c)\(\left(x+a\right)\left(x+b\right)=x^2+\left(a+b\right)x+ab\)
giúp mik nha
chiều nay nộp r
cmr nếu A= 5x + y : 19
thì B = 4x - 3y : 19 vs x y thuộc z
Tìm x biết : (đề không sai)
1.\(-4x\left(x-7\right)+4x\left(x^2-5\right)\) \(=28x^2-13\)
2.\(\left(4x^2-5x\right)\left(3x+2\right)-7x\left(x-7\right)\)= \(\left(-4+x\right)\left(-2x+3\right)+12x^3+2x^2\)
3.\(\left(-4x^2-3\right)\left(2x+5\right)-\left(8x-3\right)\) \(\left(-x^2+2\right)=-5x^2\left(x-6\right)-3x^2-4\)
4.\(\left(x-7\right)\left(x+5\right)-\left(x-3\right)\left(x-2\right)\) \(=15x^2\left(x+1\right)-\left(3x^2-1\right)\) \(\left(5x^2-2\right)-21x^2\)
5.\(\left(x-3\right)\left(-x+10\right)+\left(x-8\right)\left(x+3\right)\) \(=\left(5x^2-1\right)\left(x+3\right)-5x^3-15x^2\)
6.\(\left(-2x^2+5\right)\left(-x+3\right)-x^2\left(2x-6\right)\) \(=\left(x-1\right)\left(x+1\right)-\left(x-2\right)\left(x+4\right)\)
Tìm x:
a.\(5x-3\left\{4x-2\left[4x-3(5x-2)\right]\right\}=182\)
b.\(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=0\)
c.\(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)
Giúp mk vs!!
tìm x, biết:
\(a,-4x\left(x-7\right)+4x\left(x^2-5\right)=28x^2-13\)
\(b,\left(4x^2-5x\right)\left(3x+2\right)-7x\left(x+5\right)\) \(=\left(-4+x\right)\left(-2x+3\right)+12x^2+2x^2\)
I) Tính (rút gọn)
1) \(\left(x^2-2x-1\right).\left(x-3\right)\)
2) (x - 5).\(\left(-x^2+4x-1\right)\)
3) \(\left(\frac{1}{2}x+3\right).\left(2x^2-4x-6\right)\)
4) \(\left(2x-1\right).\left(x^2-5x+3\right)\)
5) \(\left(-x+4\right).\left(-x^2+4x-1\right)\)
(Bn nào làm đc câu nào thì làm nha)
Rút gọn biểu thức:
A=\(\text{4(x-1)(x+1)-5x(x-2)+x^2}\)
B=\(\left(y^2+2\right)\left(y-4\right)-\left(2y^2+1\right)\left(\dfrac{1}{2}y-2\right)\)
C=\(\left(3-2x\right)\left(x-2\right)-4\left(x-1\right)\left(x-3\right)-\left(x-2\right)\left(x+2\right)\)
