Christopher Columbus set sail from Spain in 1492. What year did the civil war end

Each morning papa notes the birds feeding on his bird feeder. so far this month he has see. 59 blue jays, 68 black crows, 12 red robin's and 1 cardinal. what is the probability of a blue jay being the next bird papa sees

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*

3x + 4y = 5 x- 3y = -7 solve by substitution