Please help.
Simplify the expression using imaginary numbers.
√ -49 * √ -81

On a coordinate grid, point p is at (4, 3) and point r is at (−2, −5). points q and s are a reflection of both points across the x-axis. what are the coordinates of q and s? q(−4, 3), s(2, −5) q(4, −3), s(−2, 5) q(−4, −3), s(2, 5) q(−4, 3), s(−2, 5) ; -; i can't figure it out, if someone can me with the answer, that would be nice

The wheels of a bicycle have a diameter of 70cm. how many meters will the bicycle travel if each wheel makes 50 revolutions

Answer! if you don’t mind, can you explain