(270:y-2)*30=7*120

Interpreting ":" as division, there are two common parses. Here are both:

1. If (270:y-2) means (270/y) - 2

• Then [30 * (270/y - 2)] = 7*120 = 840
• 30*(270/y - 2) = 840 → 270/y - 2 = 28 → 270/y = 30 → y = 270/30 = 9
• Check: 270/9 = 30; 30 - 2 = 28; 28*30 = 840 ✓
• Solution: y = 9

2. If (270:y-2) means 270/(y-2)

• Then (270/(y-2))30 = 7120 = 840
• 8100/(y-2) = 840 → y-2 = 8100/840 = 135/14 → y = 2 + 135/14 = 163/14 ≈ 11.64
• Solution: y = 163/14

Which interpretation matches your problem? If you intended the first, y = 9. If you intended the second, y = 163/14.