Question 451781
If we mark number of bicycles as b and number of tricycles as t then we have the following:

b is by 1 less than 4 times t  -> {{{b=4t-1}}}


Knowing that bicycle has 2 wheels and tricycle has 3 we have:

total number of wheels is 174  -> {{{2b+3t=174}}}


Substitute b in the second equation with the first:


{{{2(4t-1)+3t=174}}}  , multiply
{{{8t-2+3t   =174}}}  , combine
{{{11t-2     =174}}}  , add 2 to the both sides of equation
{{{11t       =176}}}  , divide both sides by 11
{{{  t       =16}}}   , this is the number of tricycles


{{{b=4t-1}}}       , substitute t with 16
{{{b=4*16-1=63}}}  , this is the number of bicycles


check:
2b+3t=2*63+3*16=126+48=174, OK