Question

solve using substitution method : 0.2x+0.3y=1.3 and 0.4x+ 0.5y=2.3. pair of linear equation. ch3 class 10 ncert

Answer 1

Answer:

x = 2 and y = 3

Step-by-step explanation:

Given :$0.2x+0.3y=1.3$

           $0.4x+ 0.5y=2.3$

To Find : solve using substitution method

Solution :

$0.2x+0.3y=1.3$  -----1

$0.4x+ 0.5y=2.3$ ------2

Substitute the value of x from 1 in 2

$0.4(\frac{1.3 - 0.3 y}{0.2})+ 0.5y=2.3$

$y=3$

$0.2x+0.3(3)=1.3$

$0.2x=1.3-0.9$

$x=\frac{1.3-0.9}{0.2}$

$x=2$

So, x = 2 and y = 3

Answer 2

Answer:

Step-by-step explanation:

Given :-

0.2x + 0.3y = 1.3

0.4x + 0.5y =2.3

Solution :-

0.2x + 0.3y = 1.3 ... (i)                  

0.4x + 0.5y = 2.3 ... (ii)        

       

0.2x + 0.3y = 1.3                  

Solving equation (i), we get                  

0.2x = 1.3 - 0.3y                  

Dividing by 0.2, we get                  

x = 1.3/0.2 - 0.3/0.2                  

x = 6.5 - 1.5 y ... (iii)                  

Putting the value in equation (ii), we get                  

0.4x + 0.5y = 2.3                  

⇒ (6.5 - 1.5y) × 0.4x + 0.5y = 2.3                  

⇒ 2.6 - 0.6y + 0.5y = 2.3                  

⇒ –0.1y = 2.3 - 2.6                  

⇒ y = - 0.3/-0.1                  

⇒ y = 3                  

Putting this value in equation (iii) we get                  

⇒ x = 6.5 - 1.5 y                

⇒ x = 6.5 - 1.5(3)                  

⇒ x = 6.5 - 4.5                

⇒ x = 2

               

Hence, x = 2 and y = 3.