Question

решите систему уравнений:( номера 5 и 6)

Answer 1

$left { {{3(2a-1)+6(7-b)=51} atop {2(b+6)-7(1+6b)=-39}} right. \ left { {{6a-3+42-6b=51} atop {2b+12-7-42b=-39}} right. \ left { {{6a-6b=12} atop {-40b=-44}} right. b=1.1 \ a-b=2 \ a=b+2=1.1+2=3.1$
Ответ: (3,1; 1,1)
$left { {{ frac{3x-2y}{4}- frac{4x+5}{3}=-5 } atop { frac{6x-5y}{2}+ frac{2x+y}{5}=9 }} right. \ left { {{ 3(3x-2y)- 4(4x+5)=-60 } atop {5(6x-5y)+ 2(2x+y)=90 }} right. \ left { {{ 9x-6y- 16x-20=-60 } atop {30x-25y+ 4x+2y=90 }} right. \ left { {{ -7x-6y=-40 } atop {34x-23y=90 }} right. \ left { {{ 161x+138y=920 } atop {204x-138y=540 }} right. \ 365x=1460 \ x=4 \ 161x+138y=920 \ y= frac{920-161cdot4}{138} =2$
Ответ: (4; 2)