Question

Очень срочно

(Даю 10 балов)

Answer 1

Ответ:

$190\\1) 34*(-4)=-136\\2) (-7,2)*(-7)=50,4\\3) -3\frac{1}{5} *1\frac{2}{3} =- \frac{16*5}{5*3} =-\frac{16}{3} =-5\frac{1}{3} \\4) -3\frac{5}{9} *(-1\frac{1}{8} )=\frac{32*9}{9*8} =4$

$191\\1) -14,3*0,6+5,7*(-1,4)=-8,58-7,98=-16,56\\2) (3,4-5)*(-4,12+4,04)=(-1,6)*(-0,08)=0,128\\3)\frac{5}{9} *(-3\frac{6}{7} )-(-3\frac{5}{7} )*\frac{3}{52} =(-\frac{5*27}{9*7})+(\frac{26*3}{7*52}) =(-\frac{15}{7} )+\frac{78}{364} =(-\frac{780}{364} )+\frac{78}{364}=-\frac{702}{364} =-1\frac{338}{364} \\4)(2\frac{1}{3} -3\frac{1}{4} )*(2\frac{3}{4} -0,95)=(\frac{7}{3} -\frac{13}{4} )*(2,75-0,95)=(\frac{28}{12} -\frac{39}{12} )*1,8=(-\frac{11}{12} )*\frac{18}{10} =-\frac{198}{120} =-1\frac{78}{120}$

$192\\1)(x+3)(x-4)=0\\x^2-4x+3x-12=0\\x^2-x-12=0\\x_{1} +x_{2} =1\\x_{1} *x_{2} =-12\\x_{1} =4\\x_{2} =-3\\-3; 4.$

$2)x(x+4,3)(1.8-x)=0\\x(1,8x-x^2+7,74-4,3x)=0\\x(-x^2-2,5x+7,74)=0\\x(x^2+2,5x-7,74)=0\\x_{1} =0\\x^2+2,5x-7,74=0\\D=6,25+30,96=37,21=6,1^2\\x_{2} =\frac{-2,5+6,1}{2} =\frac{3,6}{2} =1,3\\x_{3} =\frac{-2,5-6,1}{2} =\frac{-8,6}{2} =-4,3\\-4,3; 0; 1,3.$