Toán `2x.(3x – 5) – (x – 3).(5x – 1) – (x + 2)^2 = 11` 02/08/2021 By Allison `2x.(3x – 5) – (x – 3).(5x – 1) – (x + 2)^2 = 11`
Đáp án: `x=9` Giải thích các bước giải: `2x.(3x – 5) – (x – 3).(5x – 1) – (x + 2)^2 = 11` `⇒6x^2 – 10x – (5x^2 – x – 15x + 3) – (x^2 + 4x + 4) = 11` `⇒6x^2 – 10x – 5x^2 + x + 15x – 3 – x^2 – 4x – 4 = 11` `⇒2x – 7 = 11` `⇒2x = 18` `⇒x=9` Trả lời
$2x(3x-5)-(x-3).(5x-1)-(x+2)^2=11$ $6x-10x-[x(5x-1)-3(5x-1)]-(x^2+4x+4)=11$ $6x^2-10x-[5x^2-x-15x+3]-x^2-4x-4=11$ $6x^2-10x-5x^2+x+15x-3-x^2-4x-4=11$ $(6x^2-5x^2-x^2)+(-10x+x+15x-4x)+(-3-4)=11$ $2x-7=11$ $2x=18$ $→x=18:2=9$ Trả lời
Đáp án:
`x=9`
Giải thích các bước giải:
`2x.(3x – 5) – (x – 3).(5x – 1) – (x + 2)^2 = 11`
`⇒6x^2 – 10x – (5x^2 – x – 15x + 3) – (x^2 + 4x + 4) = 11`
`⇒6x^2 – 10x – 5x^2 + x + 15x – 3 – x^2 – 4x – 4 = 11`
`⇒2x – 7 = 11`
`⇒2x = 18`
`⇒x=9`
$2x(3x-5)-(x-3).(5x-1)-(x+2)^2=11$
$6x-10x-[x(5x-1)-3(5x-1)]-(x^2+4x+4)=11$
$6x^2-10x-[5x^2-x-15x+3]-x^2-4x-4=11$
$6x^2-10x-5x^2+x+15x-3-x^2-4x-4=11$
$(6x^2-5x^2-x^2)+(-10x+x+15x-4x)+(-3-4)=11$
$2x-7=11$
$2x=18$
$→x=18:2=9$