Question

Solve the system using substitution.

2x + 2y = 30
y - 4x = 0

( _ , _ )

Answer 1

( 3 , 12 )

Explanation:

2x + 2y = 30 and y - 4x = 0 are two given equation

Name The equation

2x + 2y = 30 ...(1)

y - 4x = 0

y = 4x ...(2)

Now, Put the value of y in equation 1

2x + 2y = 30

2x + 2(4x) = 30

2x + 8x = 30

10x = 30

x = 30/10

x = 3

Now,

Put the value of x in equation 2

y = 4x

y = 4(3)

y = 12

Thus, The value of x is 3 and the value of y is 12

FOR VERIFICATION ONLY:-

2x + 2y = 30 ...(1)

2(3) + 2(12) = 30

6 + 24 = 30

30 = 30

y = 4x ...(2)

12 = 4(3)

12 = 12

Hence, L.H.S = R.H.S

-TheUnknownScientist

Answer 2

x = 3

y= 12

Explanation:

2x + 2y = 30

y - 4x = 0 /*2

2x + 2y = 30

2y - 8x = 0

-----------------

10x = 30

x = 3

y= 12