Question

resolva o sistema:
{4x-6y=0
{3x-5y=-1

Answer 1

a) 4x - 6y = 0 => 4x = 6y => x = 6y/4 => x = 3y/2, substituindo em b):
b) 3x - 5y = -1 =>3(3y/2) - 5y = -1 => 9y/2 - 5y = -1 => (9y-10y)/2 = -1 => -y = -2 => y = 2
- Se x = 3y/2 e y = 2, logo:
x = 3.2/2 => x = 3

Answer 2

Determinante = $\left[\begin{array}{ccc}4&-6\\3&-5\\\end{array}\right]$ 
DET = 18-20
DET = -2
Determinante de X = $\left[\begin{array}{ccc}0&-6\\-1&-5\\\end{array}\right]$
DETx = -6+0
DETx = -6  
DETx = $\frac{-6}{-2}$
DETx = 3
Determinante de Y = $\left[\begin{array}{ccc}4&0\\3&-1\\\end{array}\right]$
DETy = 0-4
DETy = 0
DETy = $\frac{0}{3}$
DETy = 0
   P= (3,0)
Espero ter ajudado :)