Explanation:
let no of motorcycles be m and no of cars be c
4c + 2m = 124 --(1)
c + m = 39
c = 39 - m --(2)
sub (2) into (1):
4(39 - m) + 2m = 124
156 - 2m = 124
2m = 32
m = 16
therefore, c = 23
23 cars
Topic: simultaneous eqn + forming algebraic equations
If you like to venture further, do check out my insta (learntionary) where I constantly post math tips! Thanks!