Question

Choose the correct graph of the given system of equations.

y + 2x = −1
3y − x = 4

Answer 1

The correct graph is which x= -1 and y =1

Explanation:

The question is on simultaneous equations

2x+y= -1.........................(a)

-x+3y = 4

Eliminate on side of the equation;

{2x+y= -1} 3

{-x+3y = 4} 1

open brackets

6x + 3y = -3

-x + 3y = 4......................eliminate y by subtraction

7x= -7.....................divide both sides by 7

x= -7/7 = -1......................use this in (a) above

2x+y = -1

2(-1) + y = -1

-2 +y = -1

y= -1+2 = 1

hence x= -1 and y = 1