<span>(х-3у=4 x=4+3y</span>
<span>(2х+у=15 2*(4+3y)+y=15 8+6y+y=15 7y=7 y=1</span>
((1/2)*x-3*y²)²=(1/4)*x²-3xy²+9y⁴
Ответ: а=-3.
<span> (3^2)^4*5^8/15^6 = 3^(2*4)*5^8/3^6*5^6=3^(8-6)*5^(8-6)=3^2*5^2=15^2=25</span>
X∈(5π/6+2πn;7π/6+2πn,n∈)
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