Maths-

General

Easy

Question

# Solve the system of equations by elimination :

X - Y = 4

2X + Y = 5

Hint:

**HINT:** Perform any arithmetic operation and then find.

## The correct answer is: x = 3 and y = - 1

### Complete step by step solution:

Let x - y = 4…(i)

and 2x + y = 5….(ii)

On multiplying (i) with 2, we get 2( x - y = 4)

⇒ 2x - 2y = 8…(iii)

Now, we have the coefficients of in (ii) and (iii) to be the same.

On subtracting (ii) from (iii),

we get LHS to be 2x - 2y - (2x + y) = - 2y - y = - 3y

and RHS to be 8 - 5 = 3

On equating LHS and RHS, we have - 3y = 3

⇒ y = - 1

On substituting the value of in (i), we get - (- 1) = 4

⇒x + 1 = 4

⇒x = 4 - 1

⇒x = 3

Hence we get x = 3 and y = - 1

Note: We can also solve these system of equations by making the coefficients of y

to be the same in both the equations.

Hence we get x = 3 and y = - 1

Note: We can also solve these system of equations by making the coefficients of y

to be the same in both the equations.

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