Answer: she bikes for 10 hours and runs for 6
Step-by-step explanation: suppose that x equals the amount of hours she runs and y equals the amount of hours she bikes.
6x+ 18y=216
x+y=16
(This is your system of equations)
(Starting with the second equation, x+y=16)
y=-x +16 (move x to the other side by transposition)
Now that you have something that equals Y you plug it in to the other equation:
6x+18(-x+16)=216
(Start solving)
6x-18x+288=216 (used distributive property)
-12x+288=216 (Combine like terms)
-12x=-72 (use transposition again)
x=6 (divide to get x by itself)
Now you plug in the value of x into your equation for the value of “y”, y=-x+16,
Y=-6+16 (plugged in the value of x)
Y=10 (solved the equation -6+16)