Question

rezolvate (12a-1)²-1= cu 121-(11_9x)²= (2a+6b)²-24ab= a²b²-(ab-7)²= varog ajutor va dau 48 de puncte va jur

Answer 1

folosesti formula a²-b²=(a+b)(a-b), unde a=12a-1 iar b=1

(12a-1)²-1=(12a-1+1)(12a-1-1)=12a(12a-2)=24a(6a-1)

121-(11-9x)²= (11+11-9x)(11-11+9x)=9x(22-9x), am considerat in formula a=11, b=11-9z


(2a+6b)²-24ab=4a²+24ab+36b²-24ab=4a²+36b²=4(a²+9b²), am folosit formula (a+b)²=a²+2ab+b², unde am inlocuit a=2a si b=6b


a²b²-(ab-7)²=(ab+ab-7)(ab-ab+7)=7(2ab-7)