Question

AJUTOR :)
Se considera numerele naturale a si b.
a) Daca a+b=4 si a-b=2, calculati a² - b² ;
b) Daca a-b=5 si a²-b²=70, calculati a+b.

Answer 1

a) a=4-b
4-b-b=2
4-2b=2
-2b=-2
b=-2/-2
b=1
a=4-b
a=4-1
a=3
$a^{2}-b^{2}= 3^{2}-1^{2}=9-1=8$

b) (a-b)*(a+b)=$a^{2} - b^{2} =70$
5*(a+b)=70
a+b=70/5
a+b=14