21% of 0.31=

please answer this quick ill give you 15 pts.

Simplify.7x + 3y - 2 + 6x + 1 + y squared 2 you! ; )

Explain how you can use the associative property to evaluate (7x50)x4.

40 points. given: two congruent angles ∠c and ∠r are supplementary. prove: ∠r and ∠c are both right angles. it doesn't have to be exactly 10 rows.statements reasons1. 1. 2. 2. 3. 3. 4. 4. 5. 5. 6. 6. 7. 7. 8. 8. 9. 9. 10. 10.