E.472. Dacă a⨀b=a−b+2,a \bigodot b = a-b+2,a⨀b=a−b+2, calculați [(9⨀7)⨀3]⨀2\big[\big(9 \bigodot 7\big) \bigodot 3\big] \bigodot 2[(9⨀7)⨀3]⨀2 și [9⨀(7⨀3)]⨀2.\big[9 \bigodot \big(7 \bigodot 3\big)\big] \bigodot 2.[9⨀(7⨀3)]⨀2.
Răspuns: 3,3,3, respectiv 5.5.5.
[(9⨀7)⨀3]⨀2=\big[\big(9 \bigodot 7\big) \bigodot 3\big] \bigodot 2=[(9⨀7)⨀3]⨀2= [(9−7+2)⨀3]⨀2=\big[(9-7+2) \bigodot 3\big] \bigodot 2=[(9−7+2)⨀3]⨀2= (4⨀3)⨀2=(4 \bigodot 3) \bigodot 2=(4⨀3)⨀2= (4−3+2)⨀2=(4- 3+2) \bigodot 2=(4−3+2)⨀2= 3⨀2=3−2+2=3.3 \bigodot 2=3-2+2 = 3.3⨀2=3−2+2=3.
[9⨀(7−3+2)]⨀2=\big[9 \bigodot \big(7 -3 + 2\big)\big] \bigodot 2=[9⨀(7−3+2)]⨀2= (9⨀6)⨀2=(9 \bigodot 6) \bigodot 2=(9⨀6)⨀2= (9−6+2)⨀2=(9 - 6 + 2) \bigodot 2=(9−6+2)⨀2= 5⨀2=5−2+2=5.5 \bigodot 2= 5-2+2 = 5.5⨀2=5−2+2=5.