Let x be the number in the problem. When it states that x is "no more than -10", it means than it is less than or equal to -10. So, we have
x≤-10
In order to cancel out the on the left and isolate x, we multiply both sides by 
(since 
·=1). Thus, we have
x≤-10·=-15
Therefore, x≤-15
In order to cancel out the
x≤-10·
Therefore, x≤-15