Question

помогитие 2,5^3 -1,5^3
1,8^2-1,4^2
3,9^2+10,4

Answer 1

2,5³ - 1,5³ = (2,5 - 1,5)(2,5² + 2,5*1,5 + 1,5²) = 1*(6,25 + 3,75 + 2,25) = 12,25,

1,8² - 1,4² = (1,8 - 1,4)(1,8 + 1,4) = 0,4 * 3,2 = 1,28,

3,9² + 10,4 = 15,21 - 10,4 = 4,81

Answer 2

2,5³-1,5³=(5/2)³-(3/2)³=125/8-27/8=49/4
1,8²-1,4²=(3/2)²-(7/5)²=9/4-49/25=29/100
3,9²+10,4=(39/10)²+52/5=1521/1000+52/5=2561/100