How to solve the equation 3x + (100-x) △ 3 × 1 = 100

How to solve the equation 3x + (100-x) △ 3 × 1 = 100

3x+(100-x)÷3×1=100
3x+100/3-x/3=100
8x/3=200/3
x=25
I hope I can help you