Final answer:
The expression (10 + 70 - 1) + (-6r^2 - 18 + 5r) is equivalent to -6r^2 + 5r + 61.
Step-by-step explanation:
The expression (10 + 70 - 1) + (-6r^2 - 18 + 5r) can be simplified by combining like terms. Adding the numbers inside the parentheses first, we get (80 - 1) + (-6r^2 - 18 + 5r). This simplifies further to 79 + (-6r^2 + 5r - 18). Finally, we can rearrange the terms to get the expression (-6r^2 + 5r + 79 - 18).
So, the equivalent expression is -6r^2 + 5r + 61.