Question

solve question by substitution method . 5x+4y=9. 9x+7y=13​

Answer 1

Explanation:

Here the two given equations are

5x + 4y = 9 (let this equation be numbered as 1)

9x + 7y = 13 (let this equation be numbered as 2)

Now...

taking equation 1 and making x as the subject, we get

x = (9 - 4y) / 5

substituting x in equation 2

9 (9 - 4y) / 5 + 7y = 13

opening the brackets

(81 - 36y) / 5 + 7y = 13

taking LCM

81 - 36y + 35y = 65

solving the equation

81 - 65 = 36y - 35y

16 = y

thus we got y = 16

Now for x

substituting y = 16 in equation 1

5x + 4(16) = 9

5x + 64 = 9

5x = 9-64

5x = -55

x = -11

Thus we got x = (-11)

finally we got the two values as

x = (-11)

y = 16

HOPE IT HELPS