Question 415639
-1/8x=-9/10

here we have to make x the subject: meaning that x should be on one side and the constants on the other side.
if you mulyiply the equation by 8

{{{(-1/8) * x * 8 = (-9/10) * 8}}}
we get 
-x= (-9*4)/5
-x= -36/5
/-1
x= 36/5

CHECK

{{{(-1/8) * (36/5)  = (-9/10) }}}

{{{ -9/10 = -9/10}}}