8 increased by the product of a number and 7 is greater than or equal to -18

[math_celebrity]

Take this in parts:

First, the phrase, "a number" means we pick an arbitrary variable, let's call it x.

The product of a number and 7 is 7x.

8 increased by the product of 7x means we add them together.

7x + 8

Finally that entire expression is greater than or equal to -18
7x + 8 >=-18