Ответ :<span>√(20*18)*√30=√360*√30=√(36*10)*√30=6*√10*√30=6*√300=6*√(3*100)=6*10*√3=60√3</span>
2/2si2acos2a-cos2a/sin2a=(1-cos²2a)/sin2acos2a=sin²2a/sin2acos2a=sin2a/cos2a=tg2a
<span>2х^3 - 6х + 4 = 0</span>
<span>2x^3 - 2x - 4x +4 = 0</span>
<span>2x(x+1)(x-1) - 4(x-1) = 0</span>
<span>(x-1)(2x(x+1) -4) = 0</span>
<span>2x(x+1) -4 = 0 или x-1=0</span>
<span>x^2 + x - 2 = 0 x3=1</span>
<span>D=1-4(-2) = 9</span>
<span>x1=(1-3)/2=-1 или х2=(1+3)/2=2</span>
<span>ответ: -1; 1; 2</span>
<span>(a+1)²+2(a+1)-3(a-1)(a+1)</span>=<span>a²+2a+1+2a+2-3a²+3</span>=a²-3a²+2a+2a+1+2+3= -2a²+4a+6= <span>-2(a²-2a-3)
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