Toán d, ax^2+a^2y-7x-7y e, ax^2+ay-bx^2-by f, x(x+1)^2+x(x-5)-5(x+1)^2 30/06/2021 By aikhanh d, ax^2+a^2y-7x-7y e, ax^2+ay-bx^2-by f, x(x+1)^2+x(x-5)-5(x+1)^2
`a)` Sửa đề : `a^2x + a^2y – 7x – 7y` `ax^2 + a^2y – 7x – 7y` ` = (a^2x – 7x) + (a^2y -7y)` ` = x . (a^2 – 7) + y. (a^2 -7)` ` = (x+y) . (a^2 -7)` “ `b)` `ax^2 + ay – bx^2 – by` ` = (ax^2 + ay) – (bx^2 + by)` `= a . (x^2 + y) – b . (x^2 + y)` ` = (a-b) . (x^2 + y)` “ `c)` `x . (x+1)^2 + x . (x-5) – 5 . (x+1)^2` ` = [ x . (x+1)^2 – 5 . (x+1)^2 ] + x . (x-5)` ` = (x-5) . (x+1)^2 + x . (x-5)` ` = (x-5) . [ (x+1)^2 + x]` ` = (x-5). (x^2 + 2x + 1 + x)` ` = (x-5) . (x^2 + 3x+1)` Trả lời
`a)` Sửa đề : `a^2x + a^2y – 7x – 7y`
`ax^2 + a^2y – 7x – 7y`
` = (a^2x – 7x) + (a^2y -7y)`
` = x . (a^2 – 7) + y. (a^2 -7)`
` = (x+y) . (a^2 -7)`
“
`b)`
`ax^2 + ay – bx^2 – by`
` = (ax^2 + ay) – (bx^2 + by)`
`= a . (x^2 + y) – b . (x^2 + y)`
` = (a-b) . (x^2 + y)`
“
`c)`
`x . (x+1)^2 + x . (x-5) – 5 . (x+1)^2`
` = [ x . (x+1)^2 – 5 . (x+1)^2 ] + x . (x-5)`
` = (x-5) . (x+1)^2 + x . (x-5)`
` = (x-5) . [ (x+1)^2 + x]`
` = (x-5). (x^2 + 2x + 1 + x)`
` = (x-5) . (x^2 + 3x+1)`