Answer:
3:4
16
Step-by-step explanation:
Remember how I said the ratios of the areas equals the ratio of the lengths squared, like how the area equals the length squared?
You can use that here too.
If the ratio of the lengths must square to equal 9:16,
the ratio of the length should be sqrt(9):sqrt(16) = 3:4
Also, x should be 4/3 times 12 = 16.
