5) a) 9⁷ = (3²)⁷ = (3⁷)² -este patrat perfect
4⁵= (2²)⁵ =(2⁵)² - e patrat perfect
b) 7⁴ (7+1) *7² = 7⁶ *8= (7²)³ * 2³=(7² * 2)³ - e cub perfect
6) 1+8+27=36
36=36 (adevarat)
7)
n=100 +2* 99*100 :2=100 + 99*100 = 100(1+99) = 100*100=100²
patrat perfect
