Question

Пожалуйста помогите решить.

Answer 1

$1)quad sqrt{3cdot 7^2}cdot sqrt{3cdot 2^4}=sqrt{3^2cdot 7^2cdot 2^4}=3cdot 7cdot 2^2=84\\2)quad 5-2x=11-7(x+2)\\5-2x=-7x-3\\5x=-8\\x=-frac{8}{5}\\x=-1frac{3}{5}\\4)quad x=5+3sqrt6; ;; ; y=2-sqrt6\\frac{x^2}{x^2-3xy}:frac{x}{x^2-9y^2} = frac{x^2}{x(x-3y)} cdot frac{(x-3y)(x+3y)}{x}=x+3y=\\=5+3sqrt6+3(2-sqrt6)=5+3sqrt6+6-3sqrt6=11$

$3)quad a_{n}=-0,3+3,6n\\a_{11}=-0,3+3,6cdot 11=-0,3+39,6=39,3$

Answer 2

1) √(3*7²)*√(3*2⁴)=7*√3*2²*√3=7*4*3=84,
2) 5-2x=11-7(x+2)
5-2x=11-7x-14
5x=-8
x=-1,6.
3 ) aₐ=-0,3+3,6n   a₁₁-?
a₁₁=-0,3+3,6*11=-0,3+39,6=39,3.
4) (x²/(x²-3xy))/x/(x²-9y²))=(x²/(x(x-3y))/(x/((x-3y)(x+3y))=
=(x/(x-3y))/(x/((x-3y)(x+3y)=x+3y=5+3√6+3(2-√6)=5+3√6+6-3√6=11.