Question

прошу решите срочно
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Answer 1

( 1 )

$\displaystyle\\\frac{3}{4}a^2* \frac{4}{5}b^2=\frac{3*4}{4*5} a^2b^2=\frac{3}{5}a^2b^2$

Если  a = 2, а  b =  $\frac{3}{5}$ , то  

$\displaystyle\\\frac{3}{5}a^2b^2=\frac{3}{5}*2^2*(\frac{3}{5})^2=\frac{3}{5}*4*\frac{9}{25}=\frac{12}{5}*\frac{9}{25}= \frac{108}{125}$

( 2 )

$\displaystyle\\0,4ab*8b^2=3,2ab^3$

Если  a = 0,5 , а  b = 3 , то

$\displaystyle\\3,2ab^3=3,2*0,5*3^3=3,2*0,5*27=1,6*27=43,2$

( 3 )

$\displaystyle\\0,5ab^3*16a^2b=8a^3b^4$

Если  a = -0,5 , а  b = -2 , то

$\displaystyle\\8a^3b^4=8*(-0,5)^3*(-2)^4=8*(-0,125)*16=-1*16=-16$

( 4 )

$\displaystyle\\\frac{5}{18}a^3b^4* 3\frac{3}{5}a^4b^4=\frac{5}{18}a^3b^4 *\frac{18}{5}a^4b^4=a^3b^4*a^4b^4=a^7b^8$

Если  a = -0,2 , а  b = -5 , то

$a^7b^8=-0,2^7*(-5)^8=-5*(-0,2*(-5))^7=-5*1^7=-5*1=-5$