Solve the following system of equations using elimination (Do not multipy)

1) 5x - 6y = -32
3x + 6y = 48

2) -3x - 3y = 9
3x - 4y = 5

Respuesta :

1) 5x-6y=-32
3x+6y=48
5x+3x=8x
-32+48=16
16/8= 2
2) -3x-3y=9
3x-4y=5
-3y-4y=-7
9+5=14
14/-7= -2
1) 5x - 6y = -32 --> equation 1
    3x + 6y = 48  --> equation 2
eliminating y from both of the equations and adding the rest of the terms
we get,
    8x = 16
    dividing 8 on both sides
    x = 2
Substituting the value of x in equation 1
   5(2) - 6y = -32
    10 - 6y = -32
   -6y = -12 ( dividing both sides by -6)
    y = 2

2) 
-3x - 3y = 9 ---> equation 1
      3x - 4y = 5 --> equation 2
eliminating x from both equations and adding the rest of the terms
 we get,
     -7y = 14 ( dividing both sides by -7 )
      y = -2
Substituting the value of y in the equation 1
    -3x - 3(-2) =9
    -3x + 6 = 9 (subtracting both sides by -6)
     -3x = 3
     x = -1

Hope this helps you..  :)