Factorize the quadratic trinomial
by the rule:
![ax^2+bx+c=a(x-x_1)(x-x_2), \text{ where } x_1,\ x_2 \text{ are its roots. }](https://tex.z-dn.net/?f=%20ax%5E2%2Bbx%2Bc%3Da%28x-x_1%29%28x-x_2%29%2C%20%5Ctext%7B%20where%20%7D%20x_1%2C%5C%20x_2%20%5Ctext%7B%20are%20its%20roots.%20%7D%20)
1. Find the roots:
![D=(-9)^2-4\cdot 14=81-56=25,\ \sqrt{D}=5,\\ \\ x_1=\dfrac{9-5}{2}=2,\ x_2=\dfrac{9+5}{2}=7.](https://tex.z-dn.net/?f=%20D%3D%28-9%29%5E2-4%5Ccdot%2014%3D81-56%3D25%2C%5C%20%5Csqrt%7BD%7D%3D5%2C%5C%5C%20%5C%5C%20x_1%3D%5Cdfrac%7B9-5%7D%7B2%7D%3D2%2C%5C%20x_2%3D%5Cdfrac%7B9%2B5%7D%7B2%7D%3D7.%20%20)
2. Factorize the polynomial:
![x^2 - 9x + 14=(x-2)(x-7).](https://tex.z-dn.net/?f=%20x%5E2%20-%209x%20%2B%2014%3D%28x-2%29%28x-7%29.%20)
3. Only factor x-2 is given in options, then the correct choice is B.
Answer:
(x + 1)² = (2x)²
(1 + 1)² = (2(1))²
2² = 2²
4 = 4
(-1 + 1)² = (2(-13))²
(-12)² = (-26)²
Not true
x = -13 satisfies neither
Answer:
x = 8 - 3y
Step-by-step explanation:
![21y+7x=56\\\\21y-21y+7x=56-21y\\\\7x=56-21y\\\\\frac{7x=56-21y}{7}\\\\\boxed{x=8-3y}](https://tex.z-dn.net/?f=21y%2B7x%3D56%5C%5C%5C%5C21y-21y%2B7x%3D56-21y%5C%5C%5C%5C7x%3D56-21y%5C%5C%5C%5C%5Cfrac%7B7x%3D56-21y%7D%7B7%7D%5C%5C%5C%5C%5Cboxed%7Bx%3D8-3y%7D)
Hope this helps.
I believe it was a rectangle I'm not sure test it out.