Factorise:81ab^2-4B^2+12bc-9c^2​

The earth's inner core reaches temperatures that are at times greater than 9000°f. what causes this layer to remain solid despite the high temperature?

In a short paragraph, describe your hometown in terms of its population and impact. do you live in a town or a city? is your home a higher-order or lower-order settlement? how does your hometown interact with other towns in its region? (houston)

If a volcano’s magma is high in silica, the volcano will probably a. erupt quietly. b. remain dormant. c. erupt explosively. d. produce dark-colored lava.