Yesenia swims laps at a pool. For every 10 laps she swims the backstroke, she swims 15 laps of freestyle. Which ratio shows the number of laps Yesenia swims the backstroke to the number of laps she swims freestyle?

David must install fencing around a lot that is shaped like a right angle.the side of lot that runs east-west is 200 ft long.the side of the lot runs north-south is 125 ft long.calculate how many feet of fencing he will need to surround the entire lot.

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°