Question

sistema LINEAR

11x+12y=100
5x-30y=10

Answer 1

11x+12y=100(30)
  5x-30y=10(12)

330x +360y = 3000
  60x-360y = 120  
        390x = 3120
              x = 3120
                       390
        x = 8

   5x-30y=10 ==> 3y = 5.8 - 10 ==> 3y = 40-10==> 3y= 30 ==> y = 10

Answer 2

sistema LINEAR

11x+12y=100
5x-30y=10



11x+12y=100
5x-30y=10  ISOLAR  o (x)

5x = 10 + 30y
x = 10 + 30y/5
x = 2 + 6y--------------substituir o (x)

11x + 12y = 100
11(2+6y) + 12y = 100
22 + 66y + 12y = 100
78y +22 = 100
78y = 100 -22
78y = 78
y = 78/78
y = 1----------------achar o valor de (x)
x = 2 + 6y
x = 2 + 6(1)
x = 2 + 6
x = 8



VERIFICAÇÃO

11X + 12Y = 100
11(8) + 12(1) = 100
  88   + 12     = 100
         100     = 100

5x - 30y = 10
5(8) - 30(1) = 10
40 - 30 = 10
      10  = 10


V = { 8; 1}