Question

реши систему уравнений 4х+у=-10 и 5х-2у=-10

Answer 1

{4x+y=-10     ==>y=-10-4x
{5x-2y=-10

5x-2(-10-4x)=-10
5x+20+8x=-10
13x=-30
x=-30/13
y=-10-4*(-30/13)
y=-10/13