Question

Плс помогите срочно

Решите систему уравнений:
А) y-3x=9
3x+5y=9

В) х+2у=5
5х-3у=12

Б) 6х+5у=32
3х-у=2
Г) 4х-у=4
8х-3у=4

Answer 1

$left { {{y-3x=9} atop {3x+5y=9}} right. left { {{y=3x+9} atop {3x+5y=9}} right. left { {{y=3x+9} atop {3x +5(3x+9)=9}} right. left { {{y=3x+9} atop {18x+36=0}} right. left { {{y=3x+9} atop {x=-2}} right. left { {{y=3} atop {x=-2}} right. (-2;3)$

$left { {{x+2y=5} atop {5x-3y=12}} right. left { {{x=-2y+5} atop {5x-3y=12}} right. left { {{x=-2y+5} atop {5(-2y+5) - 3y = 12}} right. left { {{x=-2y+5} atop {-13y + 13 = 0}} right. left { {{x=-2y+5} atop {y=1}} right. left { {{x=3} atop {y=1}} right. (3 ; 1)$

$left { {{6x+5y=32} atop {3x-y=2}} right. left { {{6x+5y=32} atop {y=3x-2}} right. left { {{6x + 5(3x-2)=32} atop {y=3x-2}} right. left { {{21x-42 = 0} atop {y=3x-2}} right. left { {{x=2} atop {y=3x-2}} right. left { {{x=2} atop {y=4}} right. (2 ; 4)$

$left { {{4x-y=4} atop {8x-3y=4}} right. left { {{y=4x-4} atop {8x-3y=4}} right. left { {{y=4x - 4} atop {8x - 3(4x - 4) = 4}} right. left { {{y=4x - 4} atop {-4x + 8 = 0}} right. left { {{y = 4x - 4} atop {x=2}} right. left { {{y=4} atop {x=2}} right. (2 ; 4)$

Answer 2

Круто!