Hey there!
Let's write this as a ratio/proportion.
The sum of this basic ratio is 4.25.
To figure out how much of each we have for 34, we divide this 34 by 4.25, our sum of the two ingredients. This will give us a factor we can multiply our two ingredient measurements by.
34/4.25=8
Now, we multiply our two ingredients by eight.
2.75(8)=22
1.5(8)=12
Note that these two add up to make 34 tablespoons.
Therefore, we have...
22 tablespoons of olive oil and 12 tablespoons of balsamic vinegar were used in the 34 tablespoons of bread dip.
I hope this helps! Have a great day! :)