The value of the unknown number is 10.5.
Let the unknown number = x
When 20 is subtracted from the number and the result is squared which is equal to the square of the unknown number minus 20:
(x - 20)² = x² - 20
<em>expand the equation;</em>
x² - 40x + 400 = x² - 20
<em>collect similar terms together;</em>
x² - x² - 40x = -20 - 400
-40x = -420

Thus, the value of the unknown number is 10.5.
Learn more about word problem here: brainly.com/question/18336356
The answer is (D). Creating more fossil fuels.
Fossil fuels are formed by the compression of the dead matter of plants and animals within the crust of the Earth. The plants and animals that died due to some calamity millions of years ago got covered by the rocks and soil. The internal heat of the Earth and the pressure due to the weight of the rocks turned them into thick dark crude oil. This process is natural and time consuming. It is impossible to recreate this process by artificial means on a large scale to make more solid fuels.
Interestingly, mining of extra-terrestrial planets, moons and asteroids is an ongoing research and the means to do it are being prototypes in the research laboratories of NASA and other space organisations.
Asia. In certain regions the diagnosis is as high as 95% of the population.
Saturated is the answer :))
C because they need Ribosomes to make protein and most cell needs protein to survive. Mitochondria because it produce energy for the cell.
~JZ
Hope it helps.