Môn Toán Lớp 8: Tìm x: a)(x-2)^2-(x+1)(x+3)-2x=1 ; b)3x(x-7)-2x(x+2)=(x+1)-3 ; c)(x-1)(x+1)-x(x+2)=3x-1 ; d)(2x+3)^2-(x-2)(x+2)=3x(x-1)+21
Môn Toán Lớp 8: Tìm x: a)(x-2)^2-(x+1)(x+3)-2x=1 ; b)3x(x-7)-2x(x+2)=(x+1)-3 ; c)(x-1)(x+1)-x(x+2)=3x-1 ; d)(2x+3)^2-(x-2)(x+2)=3x(x-1)+21
3x(x–7)–2x(x+2)=x–2
3x2–21x–2x2–4x=x–2
x2–25x=x–2
x2–25x–x+2=0
x2–26x+2=0
x=(26+2√167)/2,(26–2√167)/2
–1–2x=3x–1
–2x=3x
2x+3x=0
5x=0
x=0