I need help plz show all work

Find the least common denominator for thesetvo rational expressions. n^2/n^2+4n+4 -3/n^2+7n+10

The area of a circle is equal to 1 dm². find the radius of the circle.

Match the following reasons with the statements given to create the proof. 1. do = ob, ao = oc sas 2. doc = aob given 3. triangle cod congruent to triangle aob vertical angles are equal. 4. 1 = 2, ab = dc if two sides = and ||, then a parallelogram. 5. ab||dc if alternate interior angles =, then lines parallel. 6. abcd is a parallelogram cpcte