Đáp án:
Giải thích các bước giải:
$#Bears$
${A}$=$x^{14}$ - ${10}$$x^{13}$ + ${10}$$x^{12}$ - ${10}$$x^{11}$ + ...+ ${10}$$x^{2}$ - ${10}$${x}$ + ${10}$
${A}$ =$9^{14}$ - ${10}$.$9^{13}$ + ${10}$.$9^{12}$ - ${10}$.$9^{11}$ + ...+${10}$.$9^{2}$ - ${10}$.${9}$ + ${10}$
${A}$= $9^{14}$ - ( ${9}$ + ${1}$ ) . $9^{13}$ + ( ${9}$ + ${1}$ ) . $9^{12}$ - ( ${9}$ + ${1}$ ) . $9^{11}$ + ... + ( ${9}$ + ${1}$ ) . $9^{2}$- ( ${9}$ + ${1}$) . ${9}$+ ${10}$
${A}$= $9^{14}$ - $9^{14}$ -$9^{13}$ + $9^{13}$ + $9^{12}$ - $9^{12}$ - $9^{11}$ + ...+$9^{3}$ - $9^{2}$ - ${9}$ + ${10}$
${A}$ = ${-9}$ + ${10}$
${A}$ = ${1}$
