Question

Please explain your answer.

Answer 1

In the original problem flip the second half to do the multiplication

Answer 2

1. Factor r^2+7r=10
((R+2)(r+5))/3=(3r-30)/(r^2-5r-50)

2. Factor out the common term 3
((R+2)(r+5))/3=(3(r-10))/(r^2-5r-50)

3. Factor r^2-5r-50
((R+2)(r+5))/3=(3(r-10))/((r-10)(r+5))

4. Simplify
((R+2)(r+5)*3(r-10))/(3(r-10)(r+5))

5. Regroup terms
(3(r+2)(r+5)(r-10))/(3(r-10)(r+5))

6. Cancel out (r-10)
(3(r+2)(r+5))/(3(r+5))

7. Cancel out 3 and (r+5)
R+2

Have a nice day