You need to distribute the 2 by multiplying it times the m and the n;
2(m +n) = 2m + 2n
X+y = -2 is the same as y = -x-2 when you subtract x from both sides
x+y = -2 is the same as 2x+2y = -4 when you multiply both sides by 2
So A, B, and C are the same equation just in a different form.
Answer: Choice D) any of the above
Basically, we have to find out what 72% of 92 minutes is. A way to do this is turn 92 minutes into a decimal: 92 / 100 = 0.92 and then multiply the decimal by 72: 0.92 x 72 = 66.24 minutes. Rounding to the nearest tenth, however, changes the number to 66.2 minutes. Hope this helps!
The gcf of numbers is the greatest common factor of the numbers, i.e. the greatest number which divides the numbers without a remainder.