1 x^2 + 5x – 6 2 5x^2 + 5xy – x – y 3 7x – 6x^2 – 2 4 x^2 + 4x + 3 5 2x^2 + 3x – 5 6 16x – 5x^2 – 3 15/11/2021 Bởi Adeline 1 x^2 + 5x – 6 2 5x^2 + 5xy – x – y 3 7x – 6x^2 – 2 4 x^2 + 4x + 3 5 2x^2 + 3x – 5 6 16x – 5x^2 – 3
`1)` `x^2+5x-6` `=x^2-x+6x-6` `=(x^2-x)+(6x-6)` `=x(x-1)+6(x-1)` `=(x-1)(x+6)` `2)` `5x^2 + 5xy – x – y` `=(5x^2 + 5xy )-(x+y)` `=5x(x+y)-(x+y)` `=(x+y)(5x-1)` `3)` `7x – 6x^2 – 2` `=4x – 6x^2 – 2 + 3x` `= (4x – 6x^2) – (2 – 3x)` `= 2x(2 – 3x) – (2 – 3x)` `4)` ` x^2 + 4x + 3` ` `= x^2 + x + 3x + 3 ` `= (x^2 + x) + (3x + 3)` `= x(x + 1) + 3(x +1)` ` = (x + 1)(x + 3)` `= (2x – 1)(2 – 3x)` `5)` ` 2x^2 + 3x – 5` `= 2x^2 – 2x + 5x – 5 ` `= (2x^2 – 2x) + (5x – 5)` `= 2x(x – 1) + 5(x – 1) ` `= (x – 1)(2x + 5)` `6)` ` 16x – 5x^2 – 3 ` `= 15x – 5x^2 – 3 + x ` `= (15x – 5x^2) – (3 – x)` `= 5x(3 – x) – (3 – x)` ` = (3 – x)(5x – 1)` Bình luận
Đáp án:
Giải thích các bước giải:
`1)` `x^2+5x-6`
`=x^2-x+6x-6`
`=(x^2-x)+(6x-6)`
`=x(x-1)+6(x-1)`
`=(x-1)(x+6)`
`2)` `5x^2 + 5xy – x – y`
`=(5x^2 + 5xy )-(x+y)`
`=5x(x+y)-(x+y)`
`=(x+y)(5x-1)`
`3)` `7x – 6x^2 – 2`
`=4x – 6x^2 – 2 + 3x`
`= (4x – 6x^2) – (2 – 3x)`
`= 2x(2 – 3x) – (2 – 3x)`
`4)` ` x^2 + 4x + 3` `
`= x^2 + x + 3x + 3 `
`= (x^2 + x) + (3x + 3)`
`= x(x + 1) + 3(x +1)`
` = (x + 1)(x + 3)`
`= (2x – 1)(2 – 3x)`
`5)` ` 2x^2 + 3x – 5`
`= 2x^2 – 2x + 5x – 5 `
`= (2x^2 – 2x) + (5x – 5)`
`= 2x(x – 1) + 5(x – 1) `
`= (x – 1)(2x + 5)`
`6)` ` 16x – 5x^2 – 3 `
`= 15x – 5x^2 – 3 + x `
`= (15x – 5x^2) – (3 – x)`
`= 5x(3 – x) – (3 – x)`
` = (3 – x)(5x – 1)`