Question

Tìm x ∈ Z, biết :

a, -5^x + (-4) . 5^x+4 - 3 . 5^x+3 = 2 . 5 ¹¹

b, 3. 5^x+2 + 4 . 5^x-3 = 19 . 5¹⁰

c, 5. 2^x + 3. 2^x+2 = 11. 6¹¹ + 2. 6¹³

Answer 1

a)-5^x.5^x+4.5^x+3+(-4)-3=2.5¹¹

5^x+6.5¹¹-2=4+3

5^x+17=7-2

5^x+17=5¹

=>x+17=1

=>x=-16

mk bt câu a thôi

Answer 2

b: \(\Leftrightarrow5^x\cdot75+5^x\cdot\dfrac{4}{125}=19\cdot5^{10}\)

\(\Leftrightarrow5^x\simeq24729\)

hay \(x\in\varnothing\)

c: \(\Leftrightarrow2^x\cdot\left(5+3\cdot4\right)=6^{11}\left(11+2\cdot36\right)\)

=>2^x=1771303273

hay \(x\in\varnothing\)