Question

.Solution of the equation x + 3y = 13, 3x + y = 7

Answer 1

$since \: x + 3y = 13 - - - - (1) \\ and \: 3x + y = 7 \\ = > y = 7 - 3x - - - (2) \\ putting \: equation \: (2) \: in \: (1) \\ therefore \: \\ (1) = > x + 3(7 - 3x) = 13 \\ = > x + 21 - 9x = 13 \\ = > 21 - 13 = 9x - x \\ = > 8 = 8x \\ = > x = 1$

Therefore, x=1

Please follow me and mark the answer as brainliest.

Answer 2

Answer :

• x = 1
• y = 4

Solution :

By elimination method :

x + 3y = 13 ______(1)

3x + y = 7 _______(2)

Multiplying equation (1) with 3 .

3x + 9y = 39 ______(3)

Substracting equation (2) from equation (3)

3x + 9y - (3x +y ) = 39 - 7

3x - 3x + 9y -y = 32

8y = 32

y = 32/8

y = 4

Using this in equation (1)

x+3y = 13

x + 3 ×4 = 13

x + 12 = 13

x = 13 -12

x = 1

$\underline{ \therefore \sf The \: value \: of \: x \: is \: 1 \: and \: y \: is \: 4.}$

Verification :

Using x = 1 and y = 4 in equation (2)

3x + y = 7

3 × 1 + 4 = 7

7 = 7

LHS = RHS

Hence verified