Просмотрел ваш LaTeX код в общем виде, у Вас х стремится к -5.
![\displaystyle \lim_{x \to-5}\frac{\sqrt{5-4x}-5}{x^2-25}=\lim_{x \to-5}\frac{(\sqrt{5-4x}-5)(\sqrt{5-4x}+5)}{(x^2-25)(\sqrt{5-4x}+5)}=\\ \\ \\ =\lim_{x \to-5}\frac{5-4x-25}{(x-5)(x+5)(\sqrt{5-4x}+5)}=\lim_{x \to-5}\frac{-4(x+5)}{(x-5)(x+5)(\sqrt{5-4x}+5)}=\\ \\ \\ =-4\lim_{x \to-5}\frac{1}{(x-5)(\sqrt{5-4x}+5)}=-4\cdot\frac{1}{(-5-5)\cdot(\sqrt{5+20}+5)}=0.04](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Clim_%7Bx%20%5Cto-5%7D%5Cfrac%7B%5Csqrt%7B5-4x%7D-5%7D%7Bx%5E2-25%7D%3D%5Clim_%7Bx%20%5Cto-5%7D%5Cfrac%7B%28%5Csqrt%7B5-4x%7D-5%29%28%5Csqrt%7B5-4x%7D%2B5%29%7D%7B%28x%5E2-25%29%28%5Csqrt%7B5-4x%7D%2B5%29%7D%3D%5C%5C%20%5C%5C%20%5C%5C%20%3D%5Clim_%7Bx%20%5Cto-5%7D%5Cfrac%7B5-4x-25%7D%7B%28x-5%29%28x%2B5%29%28%5Csqrt%7B5-4x%7D%2B5%29%7D%3D%5Clim_%7Bx%20%5Cto-5%7D%5Cfrac%7B-4%28x%2B5%29%7D%7B%28x-5%29%28x%2B5%29%28%5Csqrt%7B5-4x%7D%2B5%29%7D%3D%5C%5C%20%5C%5C%20%5C%5C%20%3D-4%5Clim_%7Bx%20%5Cto-5%7D%5Cfrac%7B1%7D%7B%28x-5%29%28%5Csqrt%7B5-4x%7D%2B5%29%7D%3D-4%5Ccdot%5Cfrac%7B1%7D%7B%28-5-5%29%5Ccdot%28%5Csqrt%7B5%2B20%7D%2B5%29%7D%3D0.04)
1) x^2-6x-14x+18+x^2=0
2x^2-20x+18=0 (делим все 2)
x^2-10x+9=0
x1=10, x2=1
2) 3x^2+4x-16-(x^2-8x+16)=0
2x^2 +12x=0( делим все на 2)
x^2+6x=0
x(x+6)=0
x1=0 x2=-6
Найдите значение выражения при a=100 .b=81 :a√b ,√ab:<span>
</span>a√b=100х9=900
,√ab: =10х9=90
<span>№3 Упростите а)√2¹⁰⁰⁰ b)√7⁵⁰⁰
</span>а)√2¹⁰⁰⁰=2 в 500ст
b)√7⁵⁰⁰ = 7 в 250 ст