Question

If 3x+5y=9 and 5x+3y=7 then What is the value of x+y? Choose the correct alternative answer for the question.
(A) 2
(B) 16
(C) 9
(D) 7

Answer 1

hello here is your answer by Sujeet yaduvanshi,,,,,


3x+5y=9 *5
5x+3y=7*3

15x+25y=45
15x+9y=21
________
16y=24
y=24/16
y=3/2


then,
5x+3*3/2=7
5x+9/2=7
5x=7/1-9/2
5x=5/2
x=5/2 /5
x=1/2


then,

value of


x+y
1/2+3/2

=} _1_+3____
2
=} 4/2
=}2



that's all


by Sujeet yaduvanshi

Answer 2

3x + 5y = 9

=> 15x + 25y = 45 -------(1)

5x + 3y = 7

=> 15x + 9y = 21 -------(2)

On subtracting equation 2 from 1, we get

16y = 24

=> y = 3/2

Now,

On substituting the value of y in equation 1, we get

3x + 15/2 = 9

=> 3x = 9 - 15/2

=> 3x = 3 / 2

=> x = 1/ 2

Now,

X + Y = 3/2 + 1/2 = 4/2 = 2