Let Bikes = B and cars = c
a bike has 2 wheels and a car has 4 wheels.
Equation 1: add bikes and cars to get total students:
b + c = 80
Equation 2: multiply the number of wheels by each type and add to equal the total wheels.
2b +4c = 270
Rewrite the first equation as b = 80- c
Now substitute that for b in the second equation:
2(80-c) + 4c = 270
Simplify:
160 - 2c + 4c = 270
160 +2c = 270
Subtract 160 from both sides:
2c = 110
Divide both sides by 2
c = 110/2
c = 55
Replace c with 55 in the first equation and solve for b:
b + 55 = 80
b = 80-55
b = 25
b = 25, c = 55
