1. Perhatikan bentuk berikut! 4x + 2y = 2
x - 2y = 4
a. Apakah merupakan sistem persamaan?
b. Ada berapa variabelnya?
C. Apa saja variabelnya?
d. Disebut bentuk apakah tersebut?​

Why is the future for life on earth bleak?

Which statements describe sustainable development? multiple answer choice -fishing does not remove more fish from water systems than can be replaced by the number of fish that will be born to replace them. -sustainable development is development that is designed to improve the economic conditions in less-developed countries. -sustainable development is mainly a regional issue. -sustainable development means water is used at a rate that won't reduce the amount available for future use. - sustainable development policies only need to be concerned with environmental protection. - trees cannot be cut down faster than the number that will be replaced by new growth.

All of the following occurred due to the invention of the railroad except