{4y+2x =4, 3y -3x = -6} solve by substatution and check answer

Question

I have done this problem several times. and can not seem to get the correct work and check.

Answer 1

(1)     4y + 2x = 4
(2)     3y - 3x = -6

 

Let's solve equation (1) for x:

4y + 2x = 4

2x = 4 - 4y

 

x = 2 - 2y

 

Now let's substitute 2-2y in place of x in equation 2:

3y - 3x = -6                     [Equation (2)]

3y - 3(2-2y) = -6              [Substituted 2-2y for x]

3y - 6 + 6y = -6

9y = 0

 

y = 0

 

Find x:

x = 2 - 2y

x = 2 - 2(0)

x=2

 

Check:

4y+2x = 4

4(0)+2(2) = 4

4 = 4

 

3y-3x=-6

3(0)-3(2) = -6

-6 = -6

 

Answer 2

Hi Adena,

 

4y+2x=4......eq 1

3y-3x=-6.......eq 2

 

Divide eq 2 by 3, we get,

 y-x=-2

adding x on both the sides,

y=x-2..........eq 3

 

substituting value of y in eq 1, we get,

4(x-2)+2x=4

4x-8+2x=4

6x=12

x=2

substituting value of x in  eq 3, we get,

y=2-2

y=0

 

Check: LHS of eq 1=4y+2x=4(0)+2(2)= 4=RHS

           

           LHS of eq 2= 3y-3x=3*0-3*2=-6 = RHS

 

Ans: { x=2,y=0}

 

 

Meena from Strongsville,OH