(1/2)√12+(1/3)√27+(1/4)√48=(1/2)√(4·3)+(1/3)√(9·3)+(1/4)√(16·3)=
=(1/2)·2√(3)+(1/3)·3√(3)+(1/4)·4√(3)=3√(<span>3)
</span>[(√64)·25]/<span>√25=8</span>·25/5=40
Ответ:
2а
1.8/0.5*2.4=1.8/1.2=1.5
2в
12-1/4*(-2)5=12-1/4*(-32)=12-1 * (-32)сокращаем = 12-1*(-8)=12-(-8)=20
4 1
5
СА
68+63+73+67+75= 346/5=69.2
рз
75-63=12
6
-3.2/0.16=-200
7
(-1.6)6 (-1.6) (-1.6)3
Объяснение:
1. а) 5 *5⁻²=5*1/5²=5*1\25=1/5=0.2
б) (1/2)⁻³=1⁻³/2⁻³=1/1/2³=8
в) (2⁻²)⁴*16²/2³=2⁻⁸*2⁸/2³=2⁰/2³=1/8
<span>4sin^2 2x-2cos^2 2x=cos8x
4*(1-cos4x)/2-2*(1+cos4x)/2=2cos</span>²4x-1
2*(1-cos4x)-(1+cos4x)=2cos²4x-1
2cos²4x-1-2+2cos4x+1+cos4x=0
2cos²4x+3cos4x-2=0
cos4x=a
2a²+3a-2=0
D=9+16=25
a1=(-3-5)/4=-2⇒cos4x=-2<-1 нет решения
а2=(-3+5)/4=1/2⇒cos4x=1/2⇒4x=+-π/3+2πk⇒x=+-π/12+πk/2,k∈z