Combine any like terms in the expression. If there are no like terms, rewrite the expression. 34y+34z+8y–17y

Ineed to know the answer to this algebra question.

How is this equation completed? i cannot find any examples in the book.

An architect builds a model of a park in the shape of a rectangle. the model is 40.64 centimeters long and 66.04 centimeters wide. one inch equals 2.54 centimeters. use the ratio table to find the ratio of the length to the sum of the length and width in inches and in simplest form. length 40.64 width 66.04 a. 8: 21 b. 13: 21 c. 21: 13 d. 21: 8