Question

Please help me the blue line is what I have to solve for

Answer 1

To simplify the expression on the left-hand side, we add the like terms. This means we add numbers to numbers and combine the terms with z.

Combining the terms with z gives

`(2z+3z-7z)+(-8+10-7\text{)}`
`-2z-5`

We see now that the term to be put on the blank on the blue line is -2z.