Question

solve : 7x+5y=12 and 3x-2y =1 by subsitution method​

Answer 1

Answer:

let the given system of equation is

7x+5y=12 (1)

3x-2y=1 (2)

From (1),we get y=(-7x/5) .....(3)

substituting y=(-7x/5) in (2),we get

3x-2 ×(-7x/5)=1

3x + 14x/5 =1

3x + 14x =1×5

17x =5

x=5/17

substituting the value of x in (3)

y=(-7x/5)

y=(-7 (5/17) /5)

y= -7/17

Answer 2

Answer:

hope the example will help you

Step-by-step explanation:

Sol. (i) We have,

x + y = 7 ….(1)

2x – 3y = 11 ….(2)

We shall eliminate x by substituting its value from one equation into the other. from equaton (1), we get

x + y = 7 ⇒ x = 7 – y

Substituting the value of x in equation (2), we get

2 × (7 – y) – 3y = 11

⇒ 14 – 2y – 3y = 11

⇒ –5y = – 3 or, y = 3/5

Now, substituting the value of y in equation (1), we get

x + 3/5 = 7 ⇒ x = 32/5.

Hence, x = 32/5 and y = 3/5