You burn 20 calories per minute biking for x minutes and 10 calories per minute walking for y minutes. You spend a total of 90 minutes biking and walking and burn 1300 calories.

I'm so close to finishing all these.

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

X2 + y 2 = 36 x + y = 6 solve the system of equations.