Question

решите пожалуйста ааа а прошу

Answer 1

4. Решить уравнение.

$(3x^2 + 9x - 5) - (7x^2 - 6x + 2) = 7 - 2x - 4x^2;$

$3x^2 + 9x - 5 - 7x^2 + 6x - 2 = 7 - 2x - 4x^2;$

$(3x^2 - 7x^2) + (9x + 6x) - 5 - 2 = 7 - 2x - 4x^2;$

$-4x^2 + 15x - 7 = 7 - 2x - 4x^2;$

$15x - 7 = 7 - 2x;$

$15x + 2x = 7 + 7;$

$17x = 14;$

$x = frac{14}{17}.$

Ответ: $frac{14}{17}$.

5. Вычислить.

1) $frac{216^5*36^3}{6^{20}} = frac{(6^3)^5*(6^2)^3}{6^{20}} = frac{6^{15}*6^6}{6^{20}}  = frac{6^{15+6}}{6^{20}} = frac{6^{21}}{6^{20}} = 6^{21-20} = 6^1 = 6.$

2) $frac{18^{14}}{6^{12}*3^{14}} = frac{(2*3^2)^{14}}{(2*3)^{12}*3^{14}} = frac{2^{14}*(3^2)^{14}}{2^{12}*3^{12}*3^{14}} = frac{2^{14}*3^{28}}{2^{12}*3^{12+14}} = frac{2^{14}*3^{28}}{2^{12}*3^{26}} =\= 2^{14-12}*3^{28-26} = 2^2*3^2 = 4*9 = 36.$

3) $(frac{6}{11})^9*(1frac{5}{6})^7 = (frac{6}{11})^9*(frac{11}{6})^7 = (frac{6}{11})^9*(frac{6}{11})^{-7 } = (frac{6}{11})^{9+(-7)} =\= (frac{6}{11})^{9-7} = (frac{6}{11})^2 = frac{6^2}{11^2} = frac{36}{121}.$

Ответ: 6; 36; $frac{36}{121}$.

6. Найти (*).

$(5x^2 - 3xy - y^2) - (*) = x^2 + 3xy;$

$(*) = (5x^2 - 3xy - y^2) - (x^2 + 3xy);$

$(*) = 5x^2 - 3xy - y^2 - x^2 - 3xy;$

$(*) = 4x^2 - 6xy - y^2.$

Ответ: 4x² - 6xy - y².