Question

If 3x+ 5y = 2 9 and 5 x + 3y = 27 then, what is the value of x + y?

Answer 1

subtracting both the equations:using elimination method
5(3x+5y)=5(29)
(5x+3y)3 =(27)3
-
=15x+25y=145
15x+9y=81
- -
= 16y=64
y=64/16
y=4
x=3

Answer 2

Hello mate!!!!!!!

Here is your solution.......

Equation 1st = 3x + 5y = 29

In this 3x = 29 - 5y

x = (29 - 5y)/3

In equation 2nd = 5x + 3y = 27

= 5 (29 - 5y/3) + 3y = 27

= 145 - 25y/3 +3y = 27

= (145 - 25y + 9y) /3 = 27

= 145 - 16y = 27 × 3

= 145 - 16y = 81

= -16y = 81 -145

= -16y = -64

= 16y = 64

= y = 64/16

= y = 4

Now putting y = 4 in equation 1st

x = (29- 5×4)/3

= x = (29 - 20)/3

= x = 9/ 3

= x = 3

=x +y = 3 +4

=x + y = 7

HOPE THIS WILL HELP YOU....