Question

Find the solution of this system of equations 4x + y = 3 4x - y = -5

Answer 1

-1/4 is the answer.

Answer 2

Answer:

y = 7/2

x = -1/8

Step-by-step explanation:

4x + y = 3-----------eqn 1

4x - y = -5----------eqn 2

Let's pick eqn 1

4x + y = 3

Let's make y the subject of the formula

y = 3 -4x

Since y = 3 - 4x, substitute the value of y into eqn 2

4x - ( 3 - 4x) = -5

Using the - to open the bracket

4x - 3 + 4x = -5

16x - 3 = -5

16x = -5 + 3

16x = -2

Divide through by 16 to get the value of x

16x/ 16 = -2/16

x = -1/8

Since we've gotten the value for x, find y using eqn 1

4x + y = 3

4(-1/8) + y = 3

-4/8 + y = 3

y = 3 + 4/8

LCM is 8

y = 24 + 4 / 8

y = 28/8 ( using 4 to divide)

y = 7/2

x = -1/8

y = 7/2