Lista de exercícios sobre operações com números reais, potenciação e radiciação.

1. EXERC´ (a) 4ax − 8ay
ICIOS
(b) x2 − 67
1. Determine o valor das express˜es
o
(c) ax − ay + 2x − 2y
2
(a) 20 − (−45) : (−3) + (−2) ·
(d) x2 + 6x + 9
(−1)3
(e) 81a2 − 18a + 1
(b) −(−2)3 + (−1)6 + (−1)0 −
√ 3 1
− 5b
(f) a
25 − 32 − 52 : 25 5
√
(g) a − b4
4
−(−2)2 − 3 27
(c)
(−3 + 5)0 − 2
6. Simplifique as fra¸˜es:
co
−2 −1
(d) 2−1 + 6 · 2
− −1
3 3
x2 + xy
−4 0 (a)
1 1 1
: ·(4−1 )2 + − 2x
(e)
2 2 6 4ac + 10ac2
(b)
9
256 · 4 12a2 c
(f)
87 a4 + a3 b − ab3 − b4
(c)
1256 · 25−3 a2 − b 2
(g)
(52 )−3 · 257 7ax + ay + 7bx + by
√ (d)
3
−1
(h) ax − ay + bx − by
√ 1 1
3
− 8 + 16 4 − (−2) + 27 3
(i)
2. Simplifique as express˜es:
o
√ √
(a) 80 + 20
√
5 4 3
16 · 18 −
(b) 5+ 9
3. Racionalize os denominadores das
express˜es:
o
1
(a) √
3
2
√1
(b) 5−2
−1
−2 −2 −2 −3
4. Se x = a−1 +b−1 e y = a +b
a +b
,
a
calcule o valor de x.y quando
a = 2 e b = 1.
5. Fatore as express˜es ao m´ximo:
o a
1

2. RESPOSTAS
1. (a) 27
(b) 0
(c)
(d) 17
(e) 3
(f) 25 = 32
(g) 54 = 625
(h) −1
(i) 5
√
2. (a) 6 5
(b) 2
√
[3]4
3. (a) 2
√
(b) 5 + 2
4
4. 3
5. (a) 4a(x − 2y)
(b) (x + 8)(x − 8)
(c) (x − y)(a + 2)
(d) (x + 3)2
(e) (9a − 1)2
1
− b)
(f) (3a
5
(g) (a + b2 )(a + b)(a − b)
2
x+y
6. (a) 2
2+5c
(b) 6a
(c) a + ab + b2
2
7x+y
(d) x−y
2