How to estimate the square root of something?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

The ratios 3: 9, 4: 12, 5: 15, and 6: 18 are a pattern of equivalent ratios in the ratio table. which is another ratio in this pattern?

Evaluate the expression. (9 + 5)(3 + 2)0