2
1
fdssssssssssssssssssssssssssfdddddddddđaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Hãy luôn nhớ cảm ơn và vote 5*
nếu câu trả lời hữu ích nhé!
`(x-10)^2-x(x+80)`
`= x^2-20x+100-x^2-80x`
`= -100x+100`
`= -100*0.98+100`
`= -98+100`
`= 2`
`----`
`(2x+9)^2-x(4x+31)`
`= 4x^2+36x+81-4x^2-31x`
`= 5x+81`
`= 5*(-16.2)+81`
`= -81+81`
`= 0`
`----`
`4x^2-28x+49`
`= (2x)^2-2*2x*7+7^2`
`= (2x-7)^2`
`= (2*4-7)^2`
`= 1^2=1`
`----`
`x^3-9x^2+27x-27`
`= x^3-3*x^2*3+3x*3^2-3^3`
`= (x-3)^3`
`= (5-3)^3`
`= 2^3=8`
`----`
`9x^2+42x+49`
`= (3x)^2+2*3x*7+7^2`
`= (3x+7)^2`
`= (3*1+7)^2`
`= 10^2=100`
`----`
`25x^2-2xy+1/25y^2`
`= (5x)^2-2*1/5y*5x+(1/5y)^2`
`= (5x-1/5y)^2`
`= [5(-1/5)-1/5(-5)]^2`
`= (-1+1)^2`
`= 0^2=0`
`----`
`27+(x-3)(x^2+3x+9)`
`= 27+x^3-3^3`
`= 27+x^3-27`
`= x^3`
`= (-3)^3`
`= -27`
`----`
`x^3+3x^2+3x+1`
`= x^3+3*x^2*1+3x*1+1^3`
`= (x+1)^3`
`= (99+1)^3`
`= 100^3`
`= 1000000`
`tt(#Zero X)`
Hãy giúp mọi người biết câu trả lời này thế nào?
Bảng tin