Question

Найдите значение выражения 2a^2b^2/9a^2-b^2 * 3a+b/ab^2 при a=2,1 b=-0,7

Answer 1

=2а^2б^2/(3а-б)(3а+б) ×(3а+б)/аб^2 =2а/(3а-б)=2×2.1/(3×2.1-(-0.7))=
=4.2/(6.3+0.7)=4.2/7=0.6

Answer 2

=(2a²b²/((3a+b)(3a-b))*((3a+b)/ab²)=
=(2*2,1²*(-0,7)²/((3*2,1+(-07))(3*2,1-(-0,7))*(6,3+(-0,7))/(2,1*(-0,7)²)=
=(2*4,41*0,49/(7*5,6))*(5,6/(2,1*0,49)=2*2,1/7=2*0,3=0,6