Question 88727
1)
  x/3+4y=30 ---- (i)
  2x-y=5    ---- (ii)

  from (i)X6 - (ii)

  2x+24y= 180
  2x-y  = 5
 -  +    -
------------
    25y = 175
  or, y = 7

substitution the value of x in (ii)

 2x-7 = 5
or, 2x = 12
or, x  = 6

Ans. x = 6
     y = 7
________________________________________________
   6x-y/4=-9  ---- (i)
   3x+2y=-30  ---- (ii)

  (i)X8 + (ii) we get

  48x-2y = -72
   3x+2y = -30
----------------
  51x    = -102
 or x    = -2

put the value of x in (ii)

 -6+2y = -2
 or 2y = -2+6
 or  y =  2

Ans. x = -2, y = 2

2)

 y=x2+2x-2  --- (i)
 y=3x+4     --- (ii)

substitution the value of y from (ii) in (i), we get

    3x+4 = x2+2x-2
or, x2-x-6=0
or, x2-3x+2x-6=0
or, (x-3)(x+2)=0
  i.e. x=3 or x=-2
from (ii)
y = 13 or y = -2