Question

Scrie si calculeaza, in doua moduri , expresii al carora rezultat este de doua ori mai mic , respectiv de patru ori mai mare decat al celor date ,dupa exemplu de mai jos.a) 468+124 b ) 238+106 c ) 1000+500 . Calculat in doua moduri .

Answer 1

$\text{a) Metoda 1: }(468+124):2=592:2=296\\(468+124)\cdot4=592\cdot4=2368\\\text{Metoda 2: }(468+124):2=468:2+124:2=234+62=296\\(468+124)\cdot4=468\cdot4+124\cdot4=1872+496=2368$

$\text{b) Metoda 1: }(238+106):2=344:2=172\\(238+106)\cdot4=344\cdot4=1376\\\text{Metoda 2: }(238+106):2=238:2+106:2=119+53=172\\(238+106)\cdot4=238\cdot4+106\cdot4=952+424=1376$

$\text{c) Metoda 1: }(1000+500):2=1500:2=750\\(1000+500)\cdot4=1500\cdot4=6000\\\text{Metoda 2: }(1000+500):2=1000:2+500:2=500+250=750\\(1000+500)\cdot4=1000\cdot4+500\cdot4=4000+2000=6000$