Assuming you are just beginning algebra- the first question asked is "How many cupcakes did Patricia bake" so let X be the number of cupcakes Patricia baked- the value you want to find.
Now each sentence becomes an equation and each part of a sentence becomes an algebraic expression:
"She put half of the cupcakes equally into six boxes". Do you see that if there were X cupcakes, half of them is X/2? And dividing those, equally, into six boxes means there are (X/2)/6= X/12 cupcakes in each box?
"And the other half equally into 14 small boxes". Again, half the cupcakes is X/2 and, dividing those equally into 14 boxes means there are (X/2)/14= X/28 cupcakes in each small box.
Finally, "There were 34 cupcakes in 3 big boxes and 8 small boxes altogether". There were, from above, X/12 cupcakes in each big box so 3(X/12)= X/4 cupcakes in 3 big boxes. There were, from above, X/28 cupcakes in each small box so 8(X/28)= 2X/7 cupcakes in 8 small boxes. That is a total of X/4+ 2X/7. We are told that this is 34 so we have the equation X/4+ 2X/7= 34 to solve for X. I don't like fractions so I would start by multiplying both sides of that equation by 4(7)= 28.