Question

comparati valorile expresiilor |a|+|b| si |a+b|, daca:
a) a=-2,8, b=1,3;
b) a=$- \frac{3}{4}$,b=$- \frac{1}{2}$;
c)a=7,1, b=4,8
cum trebuie sa fie numerele a si b, astfel incit |a+b| =|a|+|b|?

Answer 1

a) |-2.8| + |1.3| = 2.8+1.3 = 4.1
    |-2.8+1.3| =|-1.5| = 1.5 
             4.1>1.5
b) |  | + |  | = 3/4 + 1/2 = 5/4
 
     |   | =| -5/4| = 5/4
            5/4=5/4
c) |7,1| + |4.8| = 11.9
    |7.1 + 4.8 | = 11.9
              11.9=11.9