Question

(7,26)³-(2,74)³
___________________+7.26*2.74
4,52

Answer 1

$\dfrac{(7,26)^3-(2,74)^3}{4,52}+7,26\cdot 2,74=\\\\\\=\dfrac{(7,26-2,74)(7,26^2+7,26\cdot 2,74+2,74^2)}{4,52}+7,26\cdot 2,74=\\\\\\=\dfrac{4,52\cdot (7,26^2+7,26\cdot 2,74+2,74^2)}{4,52}+7,26\cdot 2,74=\\\\\\=(7,26^2+7,26\cdot 2,74+2,74^2)+7,26\cdot 2,74=\\\\\\=7,26^2+2\cdot 7,26\cdot 2,74+2,74^2=(7,26+2,74)^2=10^2=100$

Answer 2

((7.26-2.74)(7.26²+7.26*2.74+2.74²)/4.52)+7.26*2.74=

7.26²+7.26*2.74+2.74²+7.26*2.74=(7.26+2.74)²=100

Использовал формулы (а³-с³)=(а-с)(а²+ас+с²)  и а²+2ас+с²= (а+с)²