Giúp mik vs tí nx mik nộp r

`@` Chyngynz

Đáp án:

a) `(2x+3y)^2=(2x)^2+2*2x*3y+(3y)^2=4x^2+12xy+9y^2`

b) `(5x-y)^2=(5x)^2-2*5x*y+y^2=25x^2-10xy+y^2`

c) `(2x+y^2)^3=(2x)^3+3*(2x)^2*y^2+3*2x*(y^2)^2+(y^2)^3=8x^3+12x^2y^2+6xy^4+y^6`

d) `(x^2+2/5y)(x^2-2/5y)=(x^2)^2-(2/5y)^2=x^4-4/25y^2`

e) `(x+1/4)^2=x^2+2*x*1/4+(1/4)^2=x^2+1/2x+1/16`

f) `(2/3x^2-1/2y)^3=(2/3x^2)^3-3*(2/3x^2)^2*1/2y+3*2/3x^2*(1/2y)^2-(1/2y)^3=8/27x^6-2/3x^4y+1/2x^2y^2-1/8y^3`

g) `(3x^2-2y)^3=(3x^2)^3-3*(3x^2)^2*2y+3*3x^2*(2y)^2-(2y)^3=27x^6-54x^4y+36x^2y^2-8y^3`

h) `(x-3y)(x^2+3xy+9y^2)=(x-3y)[x^2+3y*x+(3y)^2]=x^3-(3y)^3=x^3-27y^3`

i) `(x^2-3)(x^4+3x^2+9)=(x^2-3)[(x^2)^2+3*x^2+3^2]=(x^2)^3-3^3=x^6-27`

j) `(x+2y+z)(x+2y-z)=(x+2y)^2-z^2=x^2+4xy+4y^2-z^2`

k) `(2x-1)(4x^2+2x+1)=(2x-1)[(2x)^2+2x*1+1^2]=(2x)^3-1^3=8x^3-1`

l) `(5+3x)^3=5^3+3*5^2*3x+3*5*(3x)^2+(3x)^3=125+225x+135x^2+27x^3`

m) `(x+2)(x^2-2x+4)=(x+2)(x^2-2*x+2^2)=x^3+2^3=x^3+8`

n) `(x-3)(x^2+3x+9)=(x-3)(x^2+3*x+3^2)=x^3-3^3=x^3-27`