a) (5 ∧ 3015 – 5 ∧ 3013 ) ÷5 ∧ 3013 b) (3 ∧ 13 × 99 – 15 × 3 ∧ 14) ÷ (3 ∧ 17 ÷ 3 ∧ 2) c) 5 ∧ 2x × 55 ∧ x d) 3 ∧ x + 3 ∧ x+1 + 3 ∧ x+2 = 243

Giải thích các bước giải:

Ta có:

\(\begin{array}{l}
a,\\
\left( {{5^{3015}} – {5^{3013}}} \right):{5^{3013}}\\
 = {5^{3015}}:{5^{3013}} – {5^{3013}}:{5^{3013}}\\
 = {5^{3015 – 3013}} – 1\\
 = {5^2} – 1\\
 = 25 – 1\\
 = 24\\
b,\\
\left( {{3^{13}}.99 – {{15.3}^{14}}} \right):\left( {{3^{17}}:{3^2}} \right)\\
 = \left( {{3^{13}}.9.11 – {{5.3.3}^{14}}} \right):{3^{17 – 2}}\\
 = \left( {{3^{13}}{{.3}^2}.11 – {{5.3}^{1 + 14}}} \right):{3^{15}}\\
 = \left( {{3^{13 + 2}}.11 – {{5.3}^{15}}} \right):{3^{15}}\\
 = \left( {{3^{15}}.11 – {{5.3}^{15}}} \right):{3^{15}}\\
 = \left( {{{6.3}^{15}}} \right):{3^{15}}\\
 = 6\\
d,\\
{3^x} + {3^{x + 1}} + {3^{x + 2}} = 243.39\\
 \Leftrightarrow {3^x} + {3^x}{.3^1} + {3^x}{.3^2} = {3^5}.3.13\\
 \Leftrightarrow {3^x}.\left( {1 + {3^1} + {3^2}} \right) = {3^6}.13\\
 \Leftrightarrow {3^x}.13 = {3^6}.13\\
 \Leftrightarrow {3^x} = {3^6}\\
 \Leftrightarrow x = 6
\end{array}\)

Đề câu c sai rồi em nhé!