Ta có: \(\left(x-18\right)-42=\left(23-43\right)-\left(70+x\right)\)
\(\Leftrightarrow x-18-42=23-43-70-x\)
\(\Leftrightarrow x-60=-90-x\)
\(\Leftrightarrow x+x=-90+60\)
\(\Leftrightarrow2x=-30\)
hay x=-15
Vậy: x=-15
\(\left(x-18\right)-42=\left(23-43\right)-\left(70+x\right)\)
\(\Leftrightarrow x-18-42=-20-70-x\)
\(\Leftrightarrow x-60=-90-x\)
\(\Leftrightarrow x+x=-90+60\)
\(\Leftrightarrow2x=-30\)
\(\Leftrightarrow x=-15\)
Ta có: (x−18)−42=(23−43)−(70+x)(x−18)−42=(23−43)−(70+x)
⇔x−18−42=23−43−70−x⇔x−18−42=23−43−70−x
⇔x−60=−90−x⇔x−60=−90−x
⇔x+x=−90+60⇔x+x=−90+60
⇔2x=−30⇔2x=−30
x=-15
Vậy: x=-15