use elimnation to solve?

Question

#1,
x/3+4y=30
2x-y=5
#2,
6x-y/4=-9
3x+2y=-30

Answer 1

[05]
#1
x/3 +4y=30
x+12y=90[multiplying both sides by 3].....(1)
2x-y=5.........(2)
Multiplying(1) by 2 and subtracting(2) from it
2x+24y=180
2x-y=5
(subtracting) 25y=175 y=175/25=7
Plugging y in (2)
2x-7=5
2x=5+7=12
x=12/2=6
x=6 and y=7 ans
#2
6x-y/4= -9
24x-y= -36[multiplying both sides by 4]....(1)
3x+2y= -30.......(2)
Multiplying eqn 1 by 2 and adding eqn 2 with it
48x-2y= -72
3x+2y= -30
(adding) 51x= -102 x=-102/51= -2
Plugging x in(2),we get
3*-2+2y= -30
-6+2y= -30
2y= -30+6= -24
y= -24/2= -12
x= -2 and y= -12

Answer 2

for elimination you want to manipulate an equation to get like terms in both equations so it can be eliminated
#1 - we can first multiply the 1st equation by 3:
x + 12y = 90 - then multiply it by 2
2x + 24y = 180 now line them up and eliminate
- 2x - y = 5
------------------------
25 y = 175
y = 7
therefore x =:
2x - 7 = 5
2x = 12
x = 6
(6, 7)

#2 - multiply the 1st by 4
24x - y = -36
multiply this by 2
48x - 2y = -72
+ 3x + 2y = -30
-----------------------
51x = -102
x = -2
therefore y =:
3(-2) + 2y = -30
-6 + 2y = -30
2y = -24
y = -12
(-2, -12)

Answer 3

Question 1
- 2x - 24y = - 180
2x - y = 5----ADD
-25y = - 175
y = 7

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

x = 6 , y = 7

Question 2
24x - y = - 36
- 24x - 16y = 240----ADD

-17y = 204
y = - 12

3x - 24 = - 30
3x = - 6
x = - 2

x = - 2 , y = - 12

Answer 4

for2 one
multiplying 6x-y/4 by 8 we get
48x-2y=-72.........................(1)
now by using elimination method, we get
48x-2y=-72
3x+2y=-30
.....................
51x=-102
x=-102/51
x=2
now substituting the value of x in eqn 2 (3x+2y)
3*2+2y=-30
2y=-30-6
y=-36/2
y= - 18
ans x=3 and
y= -18