What is the function of delta sign in maths

The uppercase delta Δ means "change in" so for example: Δx = difference between two x values.

The lowercase delta which does not have, looks like a squiggly lowercase d. It generally means "very small change in".

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.