A)<img src="https://tex.z-dn.net/?f=%20x%5E%7B2%7D%20" /> + 9x + 20 = ((x + 5)(x + 4) VERDADERO x + 5 x + 4 + 4x + 20 <img src="https://tex.z-dn.net/?f=%20x%5E%7B2%7D%20" /> + 5x <img src="https://tex.z-dn.net/?f=%20x%5E%7B2%7D%20" /> + 9x + 20
b)<img src="https://tex.z-dn.net/?f=%203x%5E%7B2%7D%20" /> - 10x + 3 = (x - 3) (3x - 1) VERDADERO x - 3 3x - 1 - x + 3
<img src="https://tex.z-dn.net/?f=%203x%5E%7B2%7D%20" /> - 9x
<img src="https://tex.z-dn.net/?f=%203x%5E%7B2%7D%20" /> - 10x + 3
c)<img src="https://tex.z-dn.net/?f=9%20x%5E%7B2%7D%20" /> - <img src="https://tex.z-dn.net/?f=16%20y%5E%7B2%7D%20" /> = (3x + 4y)(3x - 4y) VERDADERA 3X + 4Y 3X - 4Y - 12xy + 16<img src="https://tex.z-dn.net/?f=%20Y%5E%7B2%7D%20" /> <img src="https://tex.z-dn.net/?f=9%20x%5E%7B2%7D%20" /> + 12xy
se simplifican valores con signos contrarios y queda :
[img = 10] - [img = 11].