Solve the following pairs of simultaneous equations?

Question

so i can plot them on a graph
3x-4y=13
5x+3y=12

Answer 1

9x - 12y = 39
20x + 12y = 48----ADD
29x = 87
x = 3

15 + 3y = 12
3y = - 3
y = - 1

x = 3 , y = - 1

Answer 2

1) 3x-4y=13
2) 5x+3y=12 ,u multiply both the equations by 4 & 3

3(3x-4y=13 = 9x-12y=39
4(5x+3y=12 = 20x+12y=48 ,then you add both values

9x-12y=39
+ + +
20x+12y=48 = 29x=87divide both by 29
hence x=3. To get y, u substitute x by its real value so,u pick either of the equation;9(3x)-4y=13
-4y=13-9
-4y=4divide both by 12 to get,
y=-1 while x=3.......

Answer 3

y=3/4x-13/4
y=-5/3x+4

plot these in your graphics calculator (assuming you have one) and then find the intersect of these two lines.

or...

Elimination Method

3x-4y=13 equation 1
5x+3y=12 equation 2

we want to eliminate y, therefore multiply equation 1 by 3 and equation two by 4.

9x-12y=39
20x+12y=48 ---add equations together. we get

29x = 87
x=3
now substitute x=3 into equation 1.
3*3-4y=13
9-4y=13
-4y=13-9
-4y=4
y=-1

Answer 4

(3x-4y=13) times 3 = (9x-12y=39)
(5x+3y=12) times 4 =(20x+12y=48)
+12y and -12y cancel each other out so:
29x = 87 so x =3
and y = -1

Answer 5

a = -a million/4 and b = 5 8a + 5b = 23 12a + 3b = 12 and be simplified by ability of dividing by ability of three you get: 4a + b = 4, remedy for b and you get b = 4 - 4a placed 4 - 4a in for b interior the 1st equation and get 8a + 5(4 - 4a) = 23 8a + 20 - 20a = 23, simplify and remedy for a 20 - 12a = 23 -12a = 3 a = -a million/4 Now which you discovered a plug it back into between the equations and remedy for b.