Đáp án:
Giải thích các bước giải:
b)
$\sqrt{2x+3}\sqrt[3]{x+5}=x^2+x-6\\\Leftrightarrow (2x+3)^3(x+5)^2=(x^2+x-6)^6\\\Leftrightarrow 8 x^5 + 116 x^4 + 614 x^3 + 1467 x^2 + 1620 x + 675=x^12 + 6 x^11 - 21 x^10 - 160 x^9 + 195 x^8 + 1806 x^7 - 1259 x^6 - 10836 x^5 + 7020 x^4 + 34560 x^3 - 27216 x^2 - 46656 x + 46656\\\Leftrightarrow x^{12} + 6 x^{11} - 21 x^{10} - 160 x^9 + 195 x^8 + 1806 x^7 - 1259 x^6 - 10844 x^5 + 6904 x^4 + 33946 x^3 - 28683 x^2 - 48276 x + 45981=0\\\Leftrightarrow \left[\begin{array}{l}x=3\\x≈0.98429073402169586788\end{array}\right.$
