question_answer 18)

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

Answer:

                (a) \[y+3,\] Here, variable \[y\] is present. So, it is not an expression with numbers only. (b) \[(7\times 20)-8z,\]Here, variable \[z\] is present. So, it is not an expression with numbers only. (c) \[5(21-7)+7\times 2,\]Here, no variable is present. So, it is an expression with numbers only. (d) 5, Here, no variable is present. So, it is an expression with number only. (e) \[3x,\] Here, variable \[x\] is present. So, it is not an expression with numbers only. (f) \[5-5n,\] Here, variable n is present. So, it is not an expression with numbers only. (g) \[(7\times 20)-(5\times 10)-45+p.\]Here, variable p is present. So, it is not an expression with numbers only. From above it is clear that (c) and (d) are expressions with numbers only.