Toán Lớp 6: Bài 1:
a) 6.x+2 mũ19 : 2 mũ 16= 68
b)7.x=x+5 mũ 21:5 mũ 19+3.2 mũ 2 – 7 mũ0
d)2 mũ x-1=16
e)5 mũ x-1=3125
Bài 2: tính
a)3 mũ 8:3 mũ 4 +2 mũ 2.2 mũ 3
b)3.4 mũ 2- 2.3 mũ2
c) (4 mũ 6.3 mũ 4.9 mũ 5):6 mũ 12
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Toán Lớp 6: Bài 1:
a) 6.x+2 mũ19 : 2 mũ 16= 68
b)7.x=x+5 mũ 21:5 mũ 19+3.2 mũ 2 – 7 mũ0
d)2 mũ x-1=16
e)5 mũ x-1=3125
Bài 2: tính
a)3 mũ 8:3 mũ 4 +2 mũ 2.2 mũ 3
b)3.4 mũ 2- 2.3 mũ2
c) (4 mũ 6.3 mũ 4.9 mũ 5):6 mũ 12
Comments ( 2 )
a) 6x+2^19 : 2^16=68
6x+2^3=68
6x = 68 – 8
6x = 60
-> x = 10
b) x+5^21 : 5^19 + 3.2^2 – 7^0=7x
x + 5^2 + 12 – 1 = 7x
x + 37 – 1 = 7x
x + 36 = 7x
36 = 6x
-> x = 6
d) 2^(x-1) = 16
2^(x-1) = 2^4
x-1 = 4
-> x = 5
e) 5^(x-1) = 3125
5^(x-1) = 5^5
x-1 = 5
-> x = 6
Bài 2:
a) 3^8 : 3^4 + 2^2 . 2^3
= 3^4 + 2^5
= 81 + 32 = 113
b) 3 . 4^2 – 2 . 3^2
= 3 . 16 – 2. 9
= 48 – 18 = 30
c) (4^6 . 3^4 . 9^5) : 6^12
= (2^12 . 3^4 . 3^10)/(2^12 . 3^12)
= (2^12 . 3^14)/(2^12 . 3^12)
= 3^2 = 9