Question

Solve the system of linear equation by adding or subtracting : x+y=5 , x-3=3

Answer 1

Answers

x = 4 1/2

y = 1/2

Step-by-step explanation

x + y = 5 ...................... (i)

x - 3y = 3 ....................(ii)

By substitution method, first make x the subject from equation (i)

x + y = 5

x = 5 - y

Substitute x in equation (ii) with 5-y.

x - 3y = 3

(5-y) - 3y = 3

5 - y - 3y = 3

5 - 4y = 3

4y = 5-3

4y = 2

y = 2/4 = 1/2

From equation (i),

x = 5 - y

= 5 - 1/2

= 4 1/2

Answer 2

Subtract

x + y = 5

-(x - 3y = 3)

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

4y = 2

Isolate the y. Divide 4 from both sides

4y/4 = 2/4

y = 1/2

y = 1/2

Plug in 1/2 for y in one of the equations.

x + y = 5

x + (1/2) = 5

Isolate the x. Subtract 1/2 from both sides

x + 1/2 (-1/2) = 5 (-1/2)

x = 4 1/2

x = 4 1/2, y = 1/2, is your answer

hope this helps