Question

4x³ +15 = 47

4.2^x - 3 = 125

Giups mình với

Answer 1

\(4x^3+15=47\)

\(\Leftrightarrow4x^3=32\)

\(\Leftrightarrow x^3=8\)

\(\Leftrightarrow x=2\)

     

\(4\cdot2^x-3=125\)

\(\Leftrightarrow4\cdot2^x=128\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Leftrightarrow x=5\)

Answer 2

4x³ + 15 = 47

=> 4x³ = 47 - 15 = 32

=> x³ = 32 : 4 = 8 = 2³

=> x = 2 

4.2^x - 3 = 125

=> 4.2^x = 125 + 3 = 128

=> 2^x = 128 : 4 = 32 = 2⁵

=>x = 5

Answer 3

x=5 hả bn

Answer 4

4x³ +15 = 47

4x³ = 47 - 15

x³ = 32 : 4

x³ = 8

x³ = 2³

4.2^x - 3 = 125

4.2^x  = 125 + 3

4.2^x  = 128

2^x  = 128 : 4

2^x  = 32

2^x  = 25