Answer:
There are 9 bikes and 6 tricycles
Step-by-step explanation:
Let
x -----> the number of bikes
y ----> the number of tricycles
we know that
x+y=15 -------> equation A
2x+3y=36 -----> equation B
Multiply equation A by -2 both sides
-2(x+y)=15(-2)
-2x-2y=-30 ------> equation C
Adds equation B and equation C
2x+3y=36
-2x-2y=-30
----------------
3y-2y=36-30
y=6 tricycles
Find the value of x
x+y=15 ------> x+6=15 -----> x=9 bikes
therefore
There are 9 bikes and 6 tricycles