(√18 +√3)*√2 -0.5√2 =(√18*√2) +(√3*√2) -0.5√2 =√(18*2) +√(3*2) -0.5√2 =√36 +√6 -0.5√2 =6 +√6 -0.5√2
1 - sin(α/2 - 3π) - cos²α/4 + sin²α/4 = sin²α/4 + cos²α/4 + sin(3π - α/2) - cos²α/4 + sin²α/4 = 2·sin²α/4 + sin α/2 = 2sin²α/4 + 2·sin α/4·cos α/4 = 2·sin α/4·(sin α/4 + cos α/4)
cos²(π + α/4)(1 + tg²(3α/4 - 3π/2))/(sin⁻¹(9π/2 + α/2)(tg²(5π/2 - α/4) - tg²(3α/4 - 7π/2))) = cos²α/4·(1 + ctg²3α/4)·cos α/2/(ctg²α/4 - ctg²3α/4) = cos²α/4·cos α/2/(sin²3α/4·(1/sin²α/4 - 1 - (1/sin²3α/4 - 1))) = cos²α/4·cos α/2/(sin²3α/4·(1/sin²α/4 - 1/sin²3α/4)) = cos²α/4·cos α/2/(sin²3α/4 / sin²α/4 - 1) = sin²α/4·cos²α/4·cos α/2/(sin²3α/4 - sin²α/4) = sin²α/4·cos²α/4·cos α/2/((sin 3α/4 - sin α/4)(sin 3α/4 + sin α/4)) = sin²α/4·cos²α/4·cos α/2/(2·sinα/4·cos α/2·2·sin α/2·cos α/4) = sin α/4·cos α/4 / (4·sin α/2) = sin α/4·cos α/4 / (8·sin α/4·cos α/4) = 1/8
7(2х+у)-5(3+у)=6
14х+7у-15-5у=6
7у-5у=6+15-14х
2у=21-14х
у=21-14х
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2
у=10,5-7х
(3^46+3^44+3^42)/(3^42-3^39)=(3^7+3^5+3^3)/(3^3-1)=(3^7+3^5+27)/26=(2187+243+27)/26=94,5
B3=b1*q^2=6*(1\3)^2=6\9=2\3
Ответ:2\3