a) 54²=(50+4)²=50²+2*50*4+4² = 2500+400+16 = ...
b) 71² =(70+1)²=4900+140+1 = ...
c) 129²=(120+9)²=14400+2160+81= ...
d) 75² = (70+5)²=4900+700+25 = 5625 ;
e) 52*48= (50+2)(50-2) = 50² - 2² = ...
f) ...=(30+3)(30-3) = 30² - 3² = ...
g)...=(100+5)(100-5)=100²-5²= ...
h)...=(500+25)(500-25)=500²-25²= ...
Sper ca , calculele elementare le poti finaliza si singur (a) !
