Помогйте :-* pleasee
3)1-36n^4 4)(7ab+0,2)(7ab-0,2)=49a²b²-0,04
спасибо :*
(6n²+1)(-6n²+1)=(1+6n²)(1-6n²)=1²-(6n²)²=1-36n⁴ (-7ab-0.2)(0.2-7ab)=-(7ab+0.2)(0.2-7ab)=-(0.2+7ab)(0.2-7ab)=-(0.2²-(7ab)²)=-(0.04-49a²b²)=-0.04+49a²b²=49a²b²-0.04
спасибо: