Verified Answer :

Simplifying
13 = 2f + 5

 Reorder the terms:
13 = 5 + 2f

 Solving
13 = 5 + 2f

 Solving for variable 'f'.

 Move all terms containing f to the left, all other terms to the right.
 Add '-2f' to each side of the equation.
13 + -2f = 5 + 2f + -2f

 Combine like terms: 2f + -2f = 0
13 + -2f = 5 + 0
13 + -2f = 5
 Add '-13' to each side of the equation.
13 + -13 + -2f = 5 + -13

 Combine like terms: 13 + -13 = 0
0 + -2f = 5 + -13
-2f = 5 + -13

 Combine like terms: 5 + -13 = -8
-2f = -8
  Divide each side by '-2'.
f = 4

 Simplifying
f = 4

SO, f = 4

13 = 2 × 4 + 5

Hope I helped:P

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