Answers

2015-08-10T16:14:31+05:30
X/7+y/3=5
(3x+7y)/21=5
3x+7y=105   ....(i)

x/2+y/9=6
(9x+2y)/18=6
9x+2y=108   ....(ii)

now from equation (i) & (ii)

3x+7y=105 ----- x 2
9x+2y=108

9x+14y=210
9x+2y=108
-   -      -
------------------
12y=92
y=92/12 = 23/3

from equation (i)

3x+7y=105
3x+7 x 23/3 = 105
3x+161/3 = 105
3x = 105-161/3
3x = (315-161)/3
3x=154/3
x = 154/9

now, 2x+ 3y = A
2 x 154/9 + 3 x 23/3 = A
A = 308/9+23
A = (308+ 207)/9
A = 515/9
A = 57.22
0