a. To solve the equation (X-2,54)×2=29,25, we can start by dividing both sides of the equation by 2:

(X-2,54)×2 / 2 = 29,25 / 2

Simplifying, we have:

X - 2,54 = 14,625

Next, we can add 2,54 to both sides of the equation to isolate X:

X - 2,54 + 2,54 = 14,625 + 2,54

Simplifying further, we get:

X = 17,165

Therefore, the solution to the equation is X = 17,165.

b. To solve the equation X + 4,25 = 4 5/2 + 13,75, we can start by simplifying the right side of the equation:

4 5/2 + 13,75 = 9/2 + 13,75

Next, we can find a common denominator for the fractions:

9/2 + 13,75 = 9/2 + 27/2

Combining the fractions, we have:

9/2 + 27/2 = 36/2

Simplifying further, we get:

36/2 = 18

Now, we can substitute this value back into the original equation:

X + 4,25 = 18

Next, we can subtract 4,25 from both sides of the equation to isolate X:

X + 4,25 - 4,25 = 18 - 4,25

Simplifying, we have:

X = 13,75

Therefore, the solution to the equation is X = 13,75.