B =(-21) (0) + (-50) ÷ (-5)​

Css3 is the latest evolution of the cascading style sheets language and aims at extending css2.1. it brings a lot of new features and additions, like rounded corners, shadows, gradients, transitions or animations, as well as new layouts like multi-columns, flexible box or grid layouts.credits to medium for making this answer credits to google for copying this answercredits to me for putting this answer on your question