The easiest way is to use (& to memorize) the sum formula for a AP:
Sum = 1st term added to the last term & multiplied by half the number of terms
S = (a+l)n/2
S = (5 + 53)(7/2) = 203
To solve for f, you need to isolate/get the variable by itself in the equation:
4(0.5f - 0.25) = 6 + f Distribute 4 into (0.5f - 0.25)
(4)0.5f + (4)(-0.25) = 6 + f
2f - 1 = 6 + f Subtract f on both sides to get "f" on one side of the equation
2f - f - 1 = 6 + f - f
f - 1 = 6 Add 1 on both sides to get "f" by itself
f - 1 + 1 = 6 + 1
f = 7
PROOF
4(0.5f - 0.25) = 6 + f Substitute/plug in 7 into "f" since f = 7
4(0.5(7) - 0.25) = 6 + 7
4(3.5 - 0.25) = 13
4(3.25) = 13
13 = 13
Two yards is equal to six feet, one yard is 3 feet
To triple this number, you can triple the whole number, triple the fraction, then add them together.
3*3=9
1/2*3=3/2 (or 1 1/2)
Add them together.
9+1 1/2= 10 1/2
