Question

Tìm x biết

a) (5x-12):4=3¹⁸:3¹⁵

b)5x³-10²=35

c)65-4^x+2=2018⁰

d)2^x+1-2^xx=32

e)30-[4(x-2)+15]=3

f)740:(x+10)=10²-2.13

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Answer 1

a) (5x - 12 ) : 4 = 3¹⁸ : 3¹⁵

( 5x - 12 ) : 4 = 3³

( 5x - 12 ) : 4 = 27

5x - 12 = 108

5x = 120

x = 24

b) 5x³ - 10² = 35

5x³ - 100 = 35

5x³ = 135

x³ = 27

x³ = 3³

=> x = 3

c) 65 - 4^x+2 = 2018⁰

65 - 4^x+2 = 1

4^x+2 = 64

4^x+2 = 4³

x + 2 = 3

=> x = 1

Answer 2

d) 2^x+1 - 2^x = 32

2^x . ( 2 - 1 ) = 32

2^x . 1 = 32

2^x = 32

2^x = 2⁵

=> x = 5

Answer 3

e) 30 - [ 4( x - 2) + 15 ] = 3

4(x-2) + 15 = 27

4( x-2) = 12

x - 2 = 3

x = 5

f) 740 : ( x + 10 ) = 10² - 2.13

740 : ( x + 10 ) = 100 - 26

740 : ( x + 10 ) = 74

x + 10 = 10

x = 0