5 в 3 степени =125;8 в 2 степени=64;9 в 8 степени=43046721.
12-0.6у=26+0.6у
-0.6у-0.8у=26-72
-1.4у=14
у=-10
B6=b1×q5
192=6×q5
q5=32
q=2
<span>S7=(b1×(q7-1))/(q-1)=6×(2(2 в 7 степени)-1)/(2-1)=6×127=762</span>
-3/9=а/(-3)=-6/18
-а/3=-1/3
а=1
а) 2cos150° - 3tq405° =2cos(180° -30°) -3tq(360°+45°) = -2cos30° -3tq45° =
-2*√3/2 -3*1 = -√3 - 3.
б) sin 7π/6 - cos2π/3 =sin(π +π/6) -cos(π-π/3) = -sinπ/6 +cosπ/3 = -1/2 +1/2 = 0.