Question

Thu gọn đa thức:

a. x(2x+1) e. 2x(x+1)-(3x²-5)

b. y(5-x) f. (x+y) (x+y)

c. 3(2x-3y). g. (x-y) (x-y)

d. 2(x+2)+x(y-5). h. (x-y) (x+y)

M.n giúp mik nha!!!!

Answer 1

a) \(x\left(2x+1\right)\)

\(=2x^2+x\)

b) \(y\left(5-x\right)=5y-xy\)

c) \(3\left(2x-3y\right)=6x-9y\)

d) \(2\left(x+2\right)+x\left(y-5\right)\)

\(=2x+4+xy-5x\)

\(=-3x+xy+4\)

e) \(2x\left(x+1\right)-\left(3x^2-5\right)\)

\(=2x^2+2x-3x^2+5\)

\(=-x^2+2x+5\)

f) \(\left(x+y\right)\left(x+y\right)\)

\(=x^2+xy+xy+y^2\)

\(=x^2+2xy+y^2\)

g) \(\left(x-y\right)\left(x-y\right)\)

\(=x^2-xy-xy+y^2\)

\(=x^2-2xy+y^2\)

h) \(\left(x-y\right)\left(x+y\right)\)

\(=x^2-xy-xy-y^2\)

\(=x^2-2xy-y^2\)

Answer 2

a) 2(2x+1)=\(2x^2+x\)

b)y(5-x)=5y-xy

c)3(2x-3y)=6x-9y

d)2x(x+1)-(3\(x^2\)-5)=\(2x^2\)+2x-\(3x^2\)+5=-\(-x^2\)+2x+5

Answer 3

e)2(x+2)+x(y-5)=2x+4+xy-5x=4-3x+xy

f)(x+y)(x+y)=(x+y)\(^2\)=\(x^2+2xy+y^2\)

g)(x-y)(x-y)=(x-y)\(^2\)=\(x^2-2xy+y^2\)

h)(x-y)(x+y)=\(x^2-y^2\)