Вправа 201 - 300 » 228

228. Виконайте множення. a) (a- b)/3 • 15/(a^2- b^2 ) = ((a- b)•15)/(3•(a- b)(a+ b)) = 5/(a+ b); б) (a- x)/〖4m〗^2 • 15am/〖(a- x)〗^2 = ((a- x)•16an)/(〖4m〗^2 (a- 〖x)〗^2 ) = 4a/(m(a- x)); в) (a^2-c^2 )/2ac • 8/〖(a+ c)〗^2 = ((a- c)(a+ c)•8)/(2ac(a+ c)(a+ c)) = (4(a- c))/(ac(a- c)); г) (3a-3b)/(4a+4c) • 〖(a+ c)〗^2/(a^2-b^2 ) = (3(a- b)• 〖(a+ c)〗^2)/(4(a+ c)•(a- b)(a+ b)) = (3(a+ c))/(4(a+ b)); ґ) (3a+9)/〖(a+3)〗^2 • (2a-4)/(a^2-4) = (3(a+3)•2(a-2))/((a+3)(a+3)(a-2)(a+2)) = 6/((a+3)(a+2)); д) (x^2-y^2 )/12 • 0,6/((x- y)) = (0,1(x+ y))/2 = (x+ y)/20.