`2/5 : x+ 7/8=-8/11`
`=>2/5 : x=-8/11-7/8`
`=>2/5 : x=-141/88`
`=> x= 2/5 :(-141/88)`
`=> x= 2/5 xx(-88/141)`
`=>x= -176/705`
\(\dfrac{2}{5}:x+\dfrac{7}{8}=-\dfrac{8}{11}\\ \Rightarrow\dfrac{2}{5}:x=\dfrac{-8}{11}+\dfrac{-7}{8}\\ \Rightarrow\dfrac{2}{5}:x=-\dfrac{64}{88}-\dfrac{77}{88}\Rightarrow\\ \dfrac{2}{5}:x=\dfrac{141}{88}\\ \Rightarrow x=\dfrac{2}{5}:\dfrac{141}{88}\\ \Rightarrow x=\dfrac{2}{5}.\dfrac{88}{141}=\dfrac{176}{705}\)