Final answer:
To combine like terms, first distribute the parentheses and combine similar elements. Subtract 3.5x from 4.5x to get 1x or just x, then add the y and the constant 7 to arrive at the simplified expression x + y + 7.
Step-by-step explanation:
To rewrite the expression by combining like terms:
4.5x + (y - 3.5x) + 7
First, distribute any parentheses and combine the elements that are similar:
4.5x - 3.5x + y + 7
Next, combine the 'x' terms:
(4.5 - 3.5)x + y + 7
Simplify the coefficients:
1x + y + 7
Since '1x' is the same as 'x', the final expression is:
x + y + 7