Question

solve it by substitution method 3x+4y = 23/7,5x- 2y= 8/7​

Answer 1

Answer:

x = 3/7

y = 1/2

Step-by-step explanation:

Given a pair of linear equations,

3x + 4y = 23/7 ........(1)

5x - 2y = 8/7 .........(2)

Solving eqn (2), we get,

=> 2y = 5x - 8/7

Now, substitute this value in (1)

Therefore, we will get,

=> 3x + 2(2y) = 23/7

=> 3x + 2(5x - 8/7) = 23/7

=> 3x + 10x - 16/7 = 23/7

=> 13x = 23/7 + 16/7

=> 13x = 39/7

=> x = 3/7

Therefore, we will get,

=> 2y = 5(3/7) - 8/7

=> 2y = 15/7 - 8/7

=> 2y = 7/7

=> 2y = 1

=> y = 1/2

Hence, the value of x = 3/7 and y = 1/2.

Answer 2

AnswEr

The value are

x = 3/7

y = 1/2

Given

• 3x + 4y = 23/7
• 5x - 2y = 8/7

To Find

• The value of x and y

Solution

Let us consider both the equations as (1) and (2) i.e. :

$\sf{3x + 4y = \frac{23}{7} ......... (1)}$

$\sf{5x - 2y = \frac{8}{7} }$

$\sf{ \implies2(5x - 2) = 2 \times \frac{8}{7} }$

$\sf{ \implies10x - 4y = \frac{16}{7} .........(2) }$

Adding (1) and (2) we have

$\sf{\implies3x + 4y + 10x - 4y = \frac{23}{7} + \frac{16}{7} }$

$\sf{ \implies 13x = \frac{23 + 16}{7} }$

$\sf{ \implies13x = \frac{39}{7} }$

$\sf{ \implies x = \frac{39}{13 \times 7} }$

$\sf{ \bold{ \implies x = \frac{3}{7}} }$

Putting the value of x in (1) we have

$\sf{ \implies3 \times \frac{3}{7} + 4y = \frac{23}{7} }$

$\sf{ \implies 4y = \frac{23}{7} - \frac{9}{7}}$

$\sf{ \implies y = \frac{23 - 9}{7 \times 4} }$

$\sf{ \implies y = \frac{14}{28} }$

$\sf{ \bold{\implies y = \frac{1}{2}} }$