Factorise:
3x²- 3xy + xy- y²

When cell phones were first entering the market, they were relatively large and reception was undependable. all cell phones were essentially the same. but as the technology developed, many competitors entered, introducing features unique to their phones. today, cell phones are only a small fraction of the size and weight of their predecessors. consumers can buy cell phones with color screens, cameras, internet access, daily planners, or voice activation (and any combination of these features). the history of the cell phone demonstrates what marketing trend?

Explain the relationship between consumers and producers in economic growth and activity

Ahospital purchases a $500,000 magnetic resonance imaging (mri) machine that has a useful life of 9 years. the salvage value at the end of 9 years is $77,000. (a) write a linear equation that describes the value y (in dollars) of the mri machine in terms of the time t (in years), 0 ≤ t ≤ 9. (b) find the value, in dollars, of the machine after 6 years. $ (c) find the time, in years, when the value of the equipment will be $140,000. (round your answer to two decimal places.) yr