Question

Hallar los valores de (x) y (y) de lo siguiente:
1. 5x+6y=20
4x-3y=23

2. 6x-5y=-9
4x+3y=13

3. 7x-15y=1
-x-6y=8

4. 1/8x-1/5y=-11/10
1/5x+1/4y=-59/40

Ayuda con esto plis!! <3 (Procedimiento) <3

Answer 1

(1)

5x+6y=20
4x-3y=23

x = 20 -6y/5
x = 23+3y/4

Igulando:

20 -6y/5 = 23+3y/4
4(20 -6y) = 5(23+3y)
80 - 24y = 115 + 15y
- 24y - 15y = 115 - 80
-39y = 35
y = 35/-39

5x+6y=20
5x + 6(-35/39) = 20
5x -210/39 = 20
5x = 570/39
x = 950/13

Resp:
y = -35/39
x = 950/13



(2)

6x-5y=-9
4x+3y=13

x = - 9 + 5y/6
x = 13 - 3y/4

 - 9 + 5y/6 = 13 - 3y/4
20y + 18y = 78-36
y = 21/19

4x+3y=13
4x + 63/19 = 13
x = - 736/19

Resp:
x = - 736/19
y = 21/19

(3)


7x -15y =1
- x - 6y = 8

x = 1 + 15y/7
x = 8 + 6y/-1


1 + 15y/7 = 8 + 6y/-1
-1(1 + 15y) = 7(8 + 6y)
-1 - 15y = 56 + 42y
- 15y - 42y = 56 + 1
-57y = 57
y = 57/-57
y = -1

7x -15y =1
7x -15(-1) = 1
7x = 1-15
x = -14/7
x = -2

Resp:
x = -2
y = -1



(4)

1/8x-1/5y=-11/10
1/5x+1/4y=-59/40

x = -44/5 + 8y/5
x = -59/8 - 5y/4

 -44/5 + 8y/5 = -59/8 - 5y/4
8y/5 + 5y/4 = -59/8 + 44/5
57y/20 = 57/40
57y = 1140/40
57y = 57/2
y = 57/114
y = 19/38
y = 1/2


1/8x-1/5y=-11/10
x/8 -1/2/5 = -11/10
x/8 = -11/10 + 1/10
x/8 = -10/10
x = -80/10
x = -8

Resp:
x = -8
y = 1/2