Question

помогитеееее?!!!!!!!!!!!

Answer 1

1)
$\frac{5x^2}{x+5} - \frac{6x^2-3x-30}{x+5} - \frac{5-2x^2-7x}{x+5} = \frac{5x^2-(6x^2-3x-30) - (5-2x^2-7x)}{x+5} = \\ \\ = \frac{5x^2 -6x^2+3x+30 -5+2x^2+7x}{x+5} = \frac{x^2+10x+25}{x+5} = \\ \\ =\frac{x^2+2*x*5 +5^2}{x+5} = \frac{(x+5)^2}{x+5} = \frac{x+5}{1} = x+5$


2)
 $\frac{a^2}{a-2} - \frac{a^2}{a+2} - \frac{16}{a^2-4} = \frac{a^2(a+2)-a^2(a-2)-16}{a^2-2^2} = \\ \\ =\frac{a^3+2a^2 - a^3+2a^2 - 16}{(a-2)(a+2)} = \frac{4a^2-16}{a^2-2^2} = \frac{4(a^2-4)}{a^2-4} =4$


3)
$\frac{x}{x+3} + \frac{3x}{x+3} + \frac{12x+36}{x^2+6x+9} = \frac{x+3x}{x+3} + \frac{12(x+3)}{x^2+2*x*3+3^2} = \\ \\ = \frac{4x}{x+3} + \frac{12(x+3)}{(x+3)^2} = \frac{4x}{x+3} + \frac{12}{x+3}= \\ \\ = \frac{4x+12}{x+3} = \frac{4(x+3)}{x+3} = 4$

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