Question

Solve the following simultaneous equations :

4 x + 3y = 11;  3x + 4y = 10  

Answer 1

4 x + 3y = 11 ....(i)      3x + 4y = 10 ...(ii) 

4 x + 3y = 11 ....(i) 

4x = 11 - 3y

x= `(11 -3"y")/4`   ......(iii) 

Put x values in equation (2)

3x + 4y = 10

`3((11 - 3"y")/4) + 4"y" = 10`

`(33 - 9"y")/4 + 4"y" = 10`

`(33 - 9"y" + 16"y")/4 = 10`

33 + 7y = 40

7y = 40 - 33 = 7

`"y" = 7/7`

y = 1

Put y = value in equation 3

`"x" = (11 - 3"y")/4`

`= (11 - 3 xx 1)/4`

`= (11 - 3)/4`

`= 8/4`

X = 2