Write the variables, constants and terms of the following expressions.
(i)18 + x − y
(ii) 7p − 4q + 5
(iii) 29x + 13y
(iv) b + 2

If x = 2 and y = 3, then find the value of the following expressions
(i) 2x − 3y
(ii) x + y
(iii) 4y − x
(iv) x + 1 − y

Subtract:
(i) 4k from 12k
(ii) 15q from 25q
(iii) 7xyz from 17xyz.

Simplify
(i) (x + y − z) + (3x − 5y + 7z) − (14x + 7y − 6z)
(ii) p + p + 2 + p + 3 − p − 4 − p − 5 + p + 10
(iii) n + (m + 1) + (n + 2) + (m + 3) + (n + 4) + (m + 5)

Solve:
(i) x + 5 = 8
(ii) p − 3 = 7
(iii) 2x = 30
\((iv) \frac{m}{6}=5 \)
(v) 7x + 10 = 80