Question 517038
Logical thinking:
well its $2 more per hour to rent skates and safety equipment so 40/2=20
so in 20 hrs you will have spent the same amount of money
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Mathimatical way: 
{{{x}}}= how many hours
{{{40+(1.5x)=3.5x}}} subtract {{{1.5x}}} from both sides
{{{40=2x}}} divide by 2
{{{20=x}}}