Tính $\ A$ :
$\ A$ $\ =$ $\ \dfrac{11 × 3^{22} × 3^{7} – 9^{15}}{(2 × 3^{14})^{2} }$
Tính $\ A$ : $\ A$ $\ =$ $\ \dfrac{11 × 3^{22} × 3^{7} – 9^{15}}{(2 × 3^{14})^{2} }$
By Genesis
By Genesis
Tính $\ A$ :
$\ A$ $\ =$ $\ \dfrac{11 × 3^{22} × 3^{7} – 9^{15}}{(2 × 3^{14})^{2} }$
Giải thích các bước giải:
$A= \frac{11.3^{22}.3^{7}-9^{15}}{\left ( 2.3^{14} \right )^{2}}$
$= \frac{11.3^{22+7}-\left ( 3^{2} \right )^{15}}{2^{2}.\left ( 3^{14} \right )^{2}}= \frac{11.3^{29}-3^{2.15}}{2^{2}.3^{14.2}}$
$= \frac{11.3^{29}-3^{30}}{2^{2}.3^{28}}= \frac{3^{29}.\left ( 11-3 \right )}{4.3^{28}}= \frac{3.8}{4}= 6$
Ta có :
A==$\frac{11× 3^{22}×3^{7}-9^{15}}{(2×3^{14})^{2}}$
=$\frac{11 × 3^{29} – (3^{2}) ^{15} }{2^{2} × 3^{28} }$
=$\frac{11 × 3^{29} – 3^{29} ×3 }{4 × 3^{28} }$
=$\frac{[(11-3)×3^{29} ] }{4 × 3^{28} }$
=$\frac{8×3^{29} }{4 × 3^{28} }$
=$\frac{8×3}{4}$
= 6