Bài 1: Tìm số nguyên x biết:
1) x . (x + 7) = 0
2) (x + 12) . ( x - 3) = 0
3) (-x + 5) . (3 - x) = 0
4) 24 : (3x - 2) = -3
5) -45 : 5 . (-3 - 2x) = 3
6) x . (2 + x) . ( 7 - x) = 0
7) (x - 1) . (x + 2) . (-x - 3) = 0
Bài 2.Tìm số nguyên x biết
1) |x| = 4
2) |x| = 0
3) -13 . |x| = -26
4) |x - 1| = 5
5) |x + 3| = 0
6) 2 . |x + 1| = 10
7) |x -5| = (-5) + 8
8) |-9 - x| - 5 = 12
9) |x + 9| . 2 = 10
Giải hộ tui cái! Cảm ơn trước!
\(1,x.\left(x+7\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x=0\\x+7=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=-7\end{cases}}}\)
\(2,\left(x+12\right).\left(x-3\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x+12=0\\x-3=0\end{cases}\Rightarrow\orbr{\begin{cases}x=-12\\x=3\end{cases}}}\)
\(3,\left(-x+5\right).\left(3-x\right)=0\)
\(\Rightarrow\orbr{\begin{cases}-x+5=0\\3-x=0\end{cases}\Rightarrow\orbr{\begin{cases}-x=-5\\x=3\end{cases}\Rightarrow}\orbr{\begin{cases}x=5\\x=3\end{cases}}}\)
\(4,24:\left(3x-2\right)=-3\)
\(3x-2=-8\)
\(3x=-6\)
\(x=-2\)
\(5,-45:5\left(-3-2x\right)=3\)
\(5\left(-3-2x\right)=-15\)
\(-3-2x=-3\)
\(2x=0\)
\(x=0\)
\(6,x.\left(2+x\right)\left(7-x\right)=0\)
\(x=0\) hoặc \(\orbr{\begin{cases}2+x=0\\7-x=0\end{cases}\Rightarrow\orbr{\begin{cases}x=-2\\x=7\end{cases}}}\)
\(7,\left(x-1\right)\left(x+2\right)\left(-x+3\right)=0\)
TH1: x-1=0 TH2 : x+2=0 TH3: -x+3=0
x=1 x=-2 -x=-3 => x=3