Ecuaciones - Cepasanfrancisco.edurioja.org

6Soluciones a las actividades de cada epígrafe
PÁGINA 140
1 Resuelve las siguientes ecuaciones:
a) x 2 = 81 b)x 2 = 25 c) x 2 = 7 d)5x 2 = 20
e) 4x 2 = 1 f) x 2 – 9 = 0 g) x 2 + 6 = 10 h)3x 2 – 7 = x 2 +9
i) = j)
2x
–
1
= 0
50
2
5x 2
5 9
2
8
a) x = ±9 b) x = ±5 c) x = ± √7 d) x = ±2
e) x = ±
1
2
f) x = ±3 g) x = ±2 h) x = ± √8 = ±2√2
i) x = ±
4
5
j) x = ±
3
10
2 Reduce, saca factor común y resuelve.
a) x 2 – 4x = 0 b)x 2 +2x = 0 c) x 2 – x = 0
d)x 2 + x = 0 e) 3x 2 – 2x = 0 f) 5x 2 + x = 0
g) 5x 2 = 4x h)2x 2 = –x i) 2x + x 2 = 7x
j) 3x 2 – 2x = 2x 2 – 4x k) = l) +
x
=
5x
6
a) x(x – 4) = 0 b) x(x + 2) = 0 c) x(x – 1) = 0
x = 0; x = 4 x = 0; x = –2 x = 0; x = 1
2
x x
3
x
3 4
2
2
d) x(x + 1) = 0 e) x(3x – 2) = 0 f) x(5x + 1) = 0
x = 0; x = –1 x = 0; x =
2
3
x = 0; x = –
1
5
g) x(5x – 4) = 0 h) x(2x + 1) = 0 i) x(x – 5) = 0
x = 0; x =
4
5
x = 0; x = –
1
2
x = 0; x = 5
j) x(x + 2) = 0 k) x(3x – 2) = 0 l) x(x + 2) = 0
x = 0; x = –2 x = 0; x =
2
3
x = 0; x = 2
3 Calcula las soluciones aplicando la fórmula.
a) x 2 – 6x + 8 = 0 b)x 2 – 6x + 5 = 0
c) x 2 + x – 12 = 0 d)x 2 +7x + 10 = 0
e) 2x 2 – 7x + 6 = 0 f) x 2 – 2x + 1 = 0
g) x 2 +6x + 9 = 0 h)x 2 – 3x + 3 = 0
6 ± √36 – 32
a) x =
2
6 ± √4
=
2
8 x = 4; x = 2
6 ± √36 – 20 6 ± √16
b) x = = 8 x = 5; x = 1
2
2
Unidad 6. Ecuaciones
Pág. 9