Question

By Substitution Method 2x - y = 1 5x + 2y = 25​

Answer 1

Explanation:

2x-y=1 -----(i)

5x+2y=25 ------(ii)

Then, from (i) equation:

$x = \frac{y + 1}{5} \: \: - - - (iii)$

Putting this value of x in equation (ii), we get:

$5( \frac{y + 1}{5} ) + 2y = 25$

$y + 1 + 2y = 25$

$3y + 1 = 25$

$3y = 25 - 1$

$3y = 24$

$y = 8$

Now putting this value of y in

equation (iii), we get:

$x = \frac{y + 1}{5}$

$x = \frac{8 + 1}{5}$

$x = \frac{9}{5}$

hence the value of x and y is:

$x = \frac{9}{5}$

$y = 8$

hope it helps :)

Answer 2

Given:-

✯ 2x - y = 1 -(i)

✯ 5x + 2y = 25 -(ii)

To Find:-

✯ Value of x and y by substitution method.

Solution:-

From (i):-

2x - y = 1

2x = 1 + y

$x = \frac{1 + y}{2}$

Now, substitute this value of x in (ii):-

$5( \frac{1 + y}{2} ) + 2y = 25$

$\frac{5 + 5y}{2} + \frac{4y}{2} = 25$

$\frac{5 + 5y + 4y}{2} = 25$

$5 + 9y = 25 \times 2$

$5 + 9y = 50$

$9y = 50 - 5$

$9y = 45$

$y = \frac{45}{9}$

$\boxed {y = 5}$

Now, use value of y in (i):-

2x - 5 = 1

2x = 5 + 1

2x = 6

$x = \frac{6}{2}$

$\boxed {x = 3}$

Therefore, value of x and and y are:-

${\sf{\green{\underline{\underline{ x = 3 \: and \: y = 5}}}}}$