Question

35 балов  3)$frac{125b^{3} -a ^{3} }{9b ^{2} -16a ^{2} } : frac{a ^{2}+25b ^{2}+5ab }{15b ^{2} +20a} * (16a ^{2} -24ab+9b ^{2} )$  $1 ) frac{18a2-72}{4b-12} * frac{3-b}{24-24a+6a2} 2) frac{36t ^{2} -25p ^{2} }{28p ^{ fra} } : frac{(5p-6t) ^{2} }{35p}$ 

Answer 1

3)$frac{125b^3-a^3}{9b^2-16a^2} : frac{a^2+25b^2+5ab}{15b^2+20a}* (16a^2-24ab+9b^2)$
$frac{(5b-a)(a^2+5ab+25b^2)(15b^2+20a)(3b-4a)^2}{(3b-4a)(3b+4a)(a^2+5ab+25b^2)}$
$frac{5(3b^2+4a)(5b-a)}{(3b+4a)}$
1)$frac{18a^2-72}{4b-12} * frac{3-b}{24-24a+6a^2} = - frac{2(3a-6)(3a+6)(b-3)}{4(b-3)(2(3a-6)(a-2)} = frac{3a+6}{4(a-2)}$
2)$frac{36t^2-25p^2}{28p} : frac{(5p-6t)^2}{35p}= -frac{35p(5p-6t)(6t+5p)}{28p(5p-6t)^2} = - frac{5(6t+5p)}{4(5p-6t)}$