x+2=-5
x =-7
x2+2x-3=0
(=) x2-x+3x-3=0
(=) x(x-1)+3(x-1)=0
(=) (x-1)(x+3)=0
=> x-1 = 0 hoặc x+3 = 0
x = 1 x =-3
x+4 = 10
x = 6
-3x + 2 =-7
(=) -3x =-9
(=) x = 3
0.5x + 4 = -1
(=) 0.5x =-5
(=) x =-10
Chúc bạn học tốt ^^
a)x+2=-5
\(\Leftrightarrow\)x =-7
b)x2+2x-3=0
\(\Leftrightarrow\)x2-x+3x-3=0
\(\Leftrightarrow\)x(x-1)+3(x-1)=0
\(\Leftrightarrow\)(x+3)(x-1)=0
\(\Rightarrow\)x+3=0 hoặc x-1=0
\(\Rightarrow\)x=-3 hoặc x=1
c)x+4=10
\(\Leftrightarrow\)x=6
d)-3x+2=-7
\(\Leftrightarrow\)-3x =-7-2
\(\Leftrightarrow\)3x =-9
\(\Leftrightarrow\)x =-3
e)0,5x+4=-1
\(\Leftrightarrow\)0,5x =-1-4
\(\Leftrightarrow\)0,5x = -5
\(\Leftrightarrow\)x =-5:0,5
\(\Leftrightarrow\)x =-10