Question

What is the solution to the equations -4x+9y=9 and x+3y=-6

Answer 1

The solution for the given equation -4x+9y=9 and x+3y=-6 is x= -27 and y = 7

Step-by-step explanation:

• step 1 : $x_{1}$ = -4x+9y = 9 , $x_{2}$ = x+3y = -6
• step 2 : For solving in the substitution method we have to multiply the equation $x_{2}$ with 3 so we get $x_{2}$ = 3x+9y = -18
• step 3 : On solving the equations we get x = -27

       $x_{1}$ = -4x+9y = 9

     3$x_{2}$ = 3x+9y = -18 ( we have to change the sign for cancelling the y term)

              1x + 0  = 27

• step 4 : By substituting the x value in any of the equation we get the y value thus  y = 7.
• step 5 : Thus the value of x and y  is -27 and 7

Answer 2

Answer:

x=-27/7, y=-5/7. (-27/7, -5/7).

Step-by-step explanation:

-4x+9y=9

x+3y=-6

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-4x+9y=9

-3(x+3y)=-3(-6)

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-4x+9y=9

-3x-9y=18

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-7x=27

x=-27/7

-27/7+3y=-6

3y=-6-(-27/7)

3y=-6+27/7

3y=-15/7

y=(-15/7)/3

y=(-15/7)(1/3)=-15/21=-5/7