Question

Calculați în două moduri ( uitati-va la poza ) va rog repedee

Answer 1

$\it a)\ 7\cdot(3-9)=7\cdot(-6)=-42\\ \\ 7\cdot(3-9)==7\cdot3-7\cdot9=21-63=-42\\ \\ \\ b)\ -4\cdot(-8+12)=-4\cdot4=-16\\ \\ -4\cdot(-8+12)=-4\cdot(-8)-4\cdot12=32-48=-16$

$\it c)\ -5\cdot[-6-(-2)]=-5\cdot(-6+2)=-5\cdopt(-4)=20\\ \\ -5\cdot[-6-(-2)]=-5\cdot(-6+2)=-5\cdot(-6)-5\cdot2=30-10=20$

$\it d)\ (-6)\cdot7+(-6)\cdot9=-42-54=-96\\ \\ (-6)\cdot7+(-6)\cdot9=-6\cdot(7+9)=-6\cdot16=-96$

$\it f)\ -10\cdot7-(-10)\cdot9=-70+90=20\\ \\ -10\cdot7-(-10)\cdot9=-10(7-9)=-10\cdot(-2)=20$