Which out of the following are expressions with numbers only?
(a) $ y+3 $
(b) $ (7 \times 20)-8 z $
(c) $ 5(21-7)+7 \times 2 $
(d) 5
(e) $ 3 x $
,b>(f) $ 5-5 n $
(g) $ (7 \times 20)-(5 \times 10)-45+p $

To do:

We have to find expressions with only numbers.

Solution:

Variable:

A variable is denoted by a symbol that can take any real value. The value of a variable is not fixed.

The letters $x, y$ and $z$ are generally used for variables.

Therefore,

(a) $y+3$ is an expression with the variable $y$.

(b) $(7\times 20)-8z$ is an expression with the variable $z$.

(c) $5(21-7)+7\times2$ is an expression with only numbers.

(d) 5 is an expression with only numbers.

(e) $3x$ is an expression with the variable $x$.

(f) $5-5n$ is an expression with the variable $n$.

(g) $(7\times 20)-(5\times 10)-45+p$ is an expression with the variable $p$.

Therefore, $5(21-7)+7\times2$ and 5 are expressions with only numbers.