What is a true rib, a false rib, and a floating rib? why are floating ribs easily broken?

Seven pairs are called true ribs. Each rib is attached to the breastbone in the front and curves around to join on to one of the vertebrae that make up the backbone via a strip of costal cartilage.

There are three pairs of false ribs. These are attached to vertebrae but are not linked to the breastbone. Instead, each rib is attached to the rib above it by cartilage.

There are two pairs of floating ribs. These are attached only to the vertebrae of the backbone.

All ribs are fragile but the floating ribs are especially fragile because these are attached only to the vertebrae of the backbone.

complete the square on the right side of the equation;

-5(x + 0)^2 + 15

answer: d. y = -x^2 + 15

i was thinking 4.0 v hope this