⇒(/x/-1/8)=(-1/8)mũ 7 : (-1/8)mũ 5

⇒/x/-1/8=(-1/8)mũ 2 

⇒/x/-1/8=1/64

⇒/x/=1/64+1/8

⇒/x/=9/64

⇒x=9/64 hoặc x=-9/64

a)(x - 1) ^{x + 2} = (x - 1)^{x + 4}

=> (x - 1) ^{x + 4} - (x - 1)^{x + 2} = 0 

=> (x - 1)^{x + 2} . [(x - 1)² - 1] = 0

=> \(\orbr{\begin{cases}\left(x-1\right)^{x+2}=0\\\left(x-1\right)^2-1=0\end{cases}\Rightarrow\orbr{\begin{cases}\left(x-1\right)^{x+2}=0^{x+2}\\\left(x-1\right)^2=1^2\end{cases}\Rightarrow}\orbr{\begin{cases}x-1=0\\x-1=\pm1\end{cases}}}\)

Nếu x - 1 = 0

=> x = 1

Nếu x - 1 = - 1

=> x = 0

Nếu x - 1 = 1

=> x = 2

Vậy \(x\in\left\{0;1;2\right\}\)

b) \(\left(1,78^{2x-2}-1,78^x\right):1,78^x=0\)

\(\Rightarrow1,78^{2x-2}:1,78^x-1,78^x:1,78^x=0\)

\(\Rightarrow1,78^{x-2}-1=0\)

\(\Rightarrow1,78^{x-2}=1\)

\(\Rightarrow1,78^{x-2}=1,78^0\)

\(\Rightarrow x-2=0\)

\(\Rightarrow x=2\)

Vậy x = 2

Thanks you bạn nhìu😉😉😉😉😉😉

\(\left(x-3\right)\left(4x+5\right)+2019\)

\(=4x^2-7x-15+2019\)

\(=4x^2-7x+2004\)

\(=4\left(x^2-\frac{7}{4}x+501\right)\)

\(=4\left(x^2-\frac{7}{4}x+\frac{49}{64}+\frac{32015}{64}\right)\)

\(=4\left[\left(x-\frac{7}{8}\right)^2+\frac{32015}{64}\right]\)

\(=4\left[\left(x-\frac{7}{8}\right)^2\right]+\frac{32015}{16}\ge\frac{32015}{16}\)

Vậy GTNN của bt là \(\frac{32015}{16}\Leftrightarrow x-\frac{7}{8}=0\Leftrightarrow x=\frac{7}{8}\)

mk tưởng 7/4