Б)(1,2-a)(1.2+a)=1.2²-a²;
г)(1/5·a-3/7·b)(14a+b)=14/5a²-14·3/7·ab+1/5ab-3/7b²=2.8a²-5.8ab-3/7b²;
e) (2.5a+3b)(0.1b-4a)=0.25ab+0.3b²-10a²-12ab=0.3b²-11.75ab-10a²;
з)(1¹/₂x-y)(2¹/₃y-¹/₃x)=(³/₂x-y)(⁷/₃y-¹/₃x)=²¹/₆xy-⁷/₃y²-³/₆x²+¹/₃xy=²³/₆xy-⁷/₃y²-¹/₂x₂
<h3>Hello Friend,</h3>
5.1 = 2^2 + 3^2 = 4+9 = 13
5.2 = 2^3 + 3^3 = 12 + 27 = 39
5.3 = 2^4 + 3^4 = 24+81= 105
5.4 = 2^2+(a*b=-3)+3^2=4-3+9=10
5.5 = 2^3*3^2+2^2*3^3=12*9+4*27=108+108=216
Скачай программу "photo math",там пошаговое решение)))