(y-4)(y+4)=y²-4²=y²-16
(7+3y)(7-3y)=7²-(3y)²=49-9y²
(n-3m)(3m+n)=n²-9m²
(2c+9d)(9d-8c)=-54cd-16c²+81d²
(x²-5)(x²+5)=x⁴-25
(9a-b²)(9a+b²)=81a²-b⁴
(10p²)(9a+b²)=90ap²+10b²p²
(1,4-0,7y³)(0,7³+1,4)=не могу решить
(1.3а^5-0.1b⁴)(1.3a^5+0.1b4)=1.69a^10-0.39a^5b⁴-0.64b^8