Question

Solve by elimination method x + y = 5 and 2x - 3y - 4 = 0​

Answer 1

Answer:

x+y=5 −(1)

2x−3y=4 −(2)

Multiplying eqn (1) with 3 and adding to eqn (2)−

3x+3y=15

+ 2x−3y=4

__________________

5x+0y=19

∴x=

5

19

=3.8

Substituting in eqn (1)−

y=5−x=5−3.8=1.2

∴x=3.8, y=1.2

Answer 2

Answer:

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

2x – 3y – 4=0

=> 2x – 3y = 4. .....equation (ii)

we multiply by 2 in equation (i)

2( x + y = 5 )

=> 2x + 2y = 10

using elimination method :

2x + 2y = 10

2x – 3y = 4

– + –

—————————

5y = 6

y = 6/5

—————————

putting the value of y in equation (i)

X + y = 5

$x \: + \frac{6}{5} = 5 \\ \\ \frac{5x + 6}{5} = 5$

crossmultiplication

5x +6 5

——— = —

5

5x +6 = 25

5x = 25–6

5x = 19

x = 19/5