Toán Tính a, (2x+y)(y-2x) b,(2x-y)(x+y-3/2) c,(2,5x mũ 2 +x+y-1)(2x+3y) 14/07/2021 By Josie Tính a, (2x+y)(y-2x) b,(2x-y)(x+y-3/2) c,(2,5x mũ 2 +x+y-1)(2x+3y)
Đáp án: Giải thích các bước giải: $a)(2x+y)(y-2x)$ `=2xy-4x^2+y^2-2xy` `=y^2-4x^2` `b)(2x-y)(x+y-3/2)` `=2x^2+2xy-3x-xy-y^2+3/2y` `=2x^2-y^2+xy-3x+3/2y` `c)(2,5x^2+x+y-1)(2x+3y)` `=5x^3+2x^2+2xy-2x+7,5x^2y+3xy+3y^2-3y` `=5x^3+7,5x^2y+2x^2+3y^2+5xy-2x-3y` Trả lời
`a) = 2x(y-2x)+y(y-2x)` `= 2xy-4x^2+y^2-2xy` `= y^2-4x^2` `b)(2x-y)(x+y-3/2)` `=2x^2+2xy-3x-xy-y^2+3/2y` `=2x^2-y^2+xy-3x+3/2y` `c) (2,5x^2 +x+y-1)(2x+3y)` `= 2x(2,5x^2+x+y-1)+3y(2,5x^2+x+y-1)` `= 5x^3+2x^2+2xy-2x+7,5xy^2+3xy+3y^2-3y` `= 5x^3+2x^2+3y^2+7,5xy^2+5xy-2x-3y` Trả lời
Đáp án:
Giải thích các bước giải:
$a)(2x+y)(y-2x)$
`=2xy-4x^2+y^2-2xy`
`=y^2-4x^2`
`b)(2x-y)(x+y-3/2)`
`=2x^2+2xy-3x-xy-y^2+3/2y`
`=2x^2-y^2+xy-3x+3/2y`
`c)(2,5x^2+x+y-1)(2x+3y)`
`=5x^3+2x^2+2xy-2x+7,5x^2y+3xy+3y^2-3y`
`=5x^3+7,5x^2y+2x^2+3y^2+5xy-2x-3y`
`a) = 2x(y-2x)+y(y-2x)`
`= 2xy-4x^2+y^2-2xy`
`= y^2-4x^2`
`b)(2x-y)(x+y-3/2)`
`=2x^2+2xy-3x-xy-y^2+3/2y`
`=2x^2-y^2+xy-3x+3/2y`
`c) (2,5x^2 +x+y-1)(2x+3y)`
`= 2x(2,5x^2+x+y-1)+3y(2,5x^2+x+y-1)`
`= 5x^3+2x^2+2xy-2x+7,5xy^2+3xy+3y^2-3y`
`= 5x^3+2x^2+3y^2+7,5xy^2+5xy-2x-3y`