Question

solve the following equation by substitution method 7x=8y+11;8x-7y=7​

Answer 1

Simultaneous Equation:                                                                              7x-8y=11         8x-7y=7

* 7                   * -8

49x-56y=77    -64x+56y= -56

On subtracting we get,    -                                                                               15x= 21

x= 21/ -15

x= - 7/5

7* -7/5 - 8y =11

-49/5 - 8y=11

-8y = 104/5

y= -51/20

Answer 2

Answer:

Step-by-step explanation:

7x = 8y + 11

8x -7y = 7

8x = 7(y+1)

x = 7(y+1)/8

7 [7(y+1)/8] = 8y +11

49y + 49 = 64y + 88

15y = 39

y = 39/15

x = 7(39+15)/15*8

x = 378/ 120