Answer:
f = 5
Explanation:
10f + 3 = 23 + 6f
Move the variable to the left-hand side and change its sign
10f + 3 - 6f = 23
Move the constant to the right-hand side and change its sign
10f - 6f = 23 - 3
Collect like terms and Subtract the numbers
4f = 23 - 3
4f = 20
Then divide both sides of the equation by 4
f = 5