1) 113^2 - 112^2 = ( 113 - 112 )( 113 + 112 ) = 1•225 = 225
2) V 225 = 15
3) 19^2 - 11^2 = ( 19 - 11 )( 19 + 11 ) = 8•30
4) 15 : ( 8/30 ) = ( 15•30 )/ 8 = 450/8 = 56,25
5) V 56,25 = 7,5
Ответ 7,5
6х+3х+4х=65
13х=65
х=65\13
х=5
доказательства: 3*5=15
Выносишь 2а^3(а^2-1)= 2а^3( а-1)(а+1)
<span>4^sin(x)+2^(5-2sin(x))=18 </span>
<span>4^sin(x)+2^5/2^2sin(x)=18 </span>
<span>t+2^5/t=18 </span>
<span>t^2-18t+32=0 </span>
<span>t1=2 t2=16 </span>
<span>4^sin(x)=2 x=(-1)^k*п/6+пк к Є Z </span>
<span>4^sin(x)=4^2 </span>
<span>Sin(x)=2 </span>
<span>Ответ: x=(-1)^k*п/6+пк к Є Z</span>
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