In the expression 21.22 (1+x), 1+x represents the total cost of the toy including the sales tax.
The sales tax is represented by the variable x, which is written in decimal form. For example, if the sales tax is 8%, x would be 0.08.
The expression 1+x represents the total cost of the toy, including the sales tax, as the base cost of the toy (1) plus the sales tax (x).
Therefore, in the expression 21.22 (1+x), 1+x represents the total cost of the toy, including the sales tax.