How would I solve this (2/3) / (3/4)

To divide fractions, we need to flip/invert/turn upside down the second fraction (the one you are dividing by). Then multiply the first fraction by the flipped fraction as normal. So, flipping the second fraction gives 4/3. Then we multiply by the first fraction: 2/3 * 4/3. This gives us 8/9.