a, 15.x = - 75
x = - 75 : 15
x = - 5
b, 3./x/ = 18
/x/ = 18 : 3
/x/ = 6
=> x = 6 hoặc x = - 6
a, 15x = -75
x = ( -75 ) : 15
x = -5
Vậy x = -5
b, 3|x| = 18
|x| = 18 : 3
|x| = 6
\(\Rightarrow\) x \(\in\) { 6;-6 }
Vậy x \(\in\) { 6;-6 }
a) \(15x=-75\)
\(\Leftrightarrow\)\(x=-75\div15\)
\(\Leftrightarrow\)\(x=-3\)
Vậy...
b) \(3\left|x\right|=18\)
\(\Leftrightarrow\)\(\left|x\right|=18\div3\)
\(\Leftrightarrow\)\(\left|x\right|=6\)
\(\Leftrightarrow\)\(x=\pm6\)
Vậy...
a) x= -75 : 15
x=-5
b)/x/ = 18 : 3
/x/= 6
x= 6 hoac -6
