Matematicas

SOLUCION TALLER
1. Halla el valor de x
a. 3 ( x -2) = 7 – (3 +2x)
3 x – 6 = 7 – 3 - 2x
3x + 2x = 7 – 3 + 6
x = 10 = 2
5

b. 5x + ½ = 7x + 3/2
5x - 7x = 3/2 – 1/2
-2x = 1
x = - 1 / 2 x= - 0,5

c. -2 [ 5x +3 ] = 3( 2x +4 )
- 10x – 6 = 6 x + 12
- 10 x – 6x = 12 + 6
- 16x = 18
x = - 18 = - 1.125
16

d. (3x –4 ) ( 4) = 5 – 3 (x +2)
12x - 16 = 5 – 3 x – 6
12x + 3x = 16 + 5 – 6
15 x = 15 x = 1

2. Halla el valor de x y y mediante uno de los métodos de solución estudiadosa. 2x + 3y = 12
3x + 2y = 13
2x = 12 – 3 y
x = 12 – 3 y
2

Sustituyo
3 12 – 3y + 2y = 13
2
36 – 9 y + 2y = 13
2
36 – 9 y + 4y =13
2
36 – 5 y = 13 * 2
36 – 5y = 26
- 5 y = 26 – 36
y = - 10 y = 2
- 5

Sustituyo
2x + 3y = 12
2x + 6 = 12
2x = 12 - 6
x = 6 . x=3
2

b. 5x – y = 7
3x + 2y = 12
5x = 7 + y
x = 7 + y
5
Sustituyo
3 7 + y + 2y = 12
5
21 + 3 y + 10y = 125
21 + 13 y = 12 * 5
13 y = 60 - 21
y = 39 y = 3
13

Sustituyo
5x - 3 = 7
5x = 10
x = 2

c. 3x + 2y = 12
X – 2y = 11
3x = 12 - 2y
x =12 – 2y
3

Sustituyo
12 - 2y - 2y = 11
3
12 - 2 y - 6y = 11
3
12 - 8 y = 11 * 3
-8 y = 33 - 12
y = 21 y = 2.625
-8
Sustituyo
x – 2y = 11
x – 2 (2.625) = 11
x – 5.25 = 11
x = 16.25

d. 5x – 6y = 3
2x + 3y = 3
5x = 3 + 6y
x = 3 + 6y
5
Sustituyo
2 3 + 6y + 3y = 3
5
6 +12 y +15y = 3
5
6 + 27 y= 3 * 5
27 y = 15 – 6
y = 11 y =0.41
27
Sustituyo
5x - 6 y = 3
5x – 6 (0.41) = 3
5x – 2.46 = 3
5x = 3 + 2.46
5x =5.46
x =1.092