a·b = 672
(a+10)b = 992 ⇒ b= [tex] \frac{992}{a+10} [/tex]
a · [tex] \frac{992}{a+10} [/tex] = 672
[tex] \frac{992a}{a+10} [/tex]=672 (inmultim pe diagonala)
992a = 672(a+10)
992a= 672a + 6720
992a-672a = 6720
320a= 6720
a = 21
b= [tex] \frac{992}{a+10} [/tex]=[tex] \frac{992}{21+10} [/tex]= [tex] \frac{992}{31} [/tex] = 32