Question

Câu 6 : Tìm x e N biết:

a) x+ 3 = 10

b) (3x - 4 ) : 2^3 = 64

Answer 1

a) x+ 3 = 10

=> x=10-3

=> x=7

vậy x=7

b) (3x - 4 ) : 2³ = 64

=> 3x-4=64.2³

=> 3x-4=2⁶.2³

=> 3x-4=2⁹

=> 3x-4=512

=> 3x=512+4

=> 3x=516

=> x=516:3

=> x=172

vậy x=172

Answer 2

a) \(x+3=10\)

\(\Leftrightarrow x=10-3\)

\(\Leftrightarrow x=7\)

Vậy \(x=7\)

b) \(\left(3x-4\right):2^3=64\)

\(\Leftrightarrow3x-4=64.2^3\)

\(\Leftrightarrow3x-4=2^6.2^3\)

\(\Leftrightarrow3x-4=2^{6+3}\)

\(\Leftrightarrow3x-4=2^9\)

\(\Leftrightarrow3x-4=512\)

\(\Leftrightarrow3x=512+4\)

\(\Leftrightarrow3x=516\)

\(\Leftrightarrow x=516:3\)

\(\Leftrightarrow x=172\)

Vậy \(x=172\)

Answer 3

a) x + 3 = 10

-> x = 10-3

-> x = 7

Vậy x = 7

b) (3x - 4 ) : 2^3 = 64

-> (3x - 4 ) : 8 = 64

-> 3x - 4 = 64 . 8

-> 3x - 4 = 512

-> 3x = 512 + 4

-> 3x = 156

-> x = 156 : 3

-> x = 52

Vậy x = 52