Question

Dacă, a-b=379 şi a= 4b+16, aflați valorile lui a şi b. Vă rog! Este urgent.

Answer 1

$\left \{ {{a-b=379} \atop {a=4b+16}} \right. \left \{ {{4b+16-b=379} \atop {a=4b+16}} \right. \left \{ {{3b+16=379} \atop {a=4b+16}} \right. \left \{ {{3b=379-16} \atop {a=4b+16}} \right.$$\left \{ {{3b=363} \atop {a=4b+16}} \right. \left \{ {{b=363 : 3} \atop {a=4b+16}} \right. \left \{ {{b=121} \atop {a=4b+16}} \right. \left \{ {{b=121} \atop {a=4 x 121+16}} \right. \left \{ {{b=121} \atop {a=484+16}} \right. \left \{ {{b=121} \atop {a=500}} \right.$

Answer 2

Algebric avem:  

a - b = 379 
a = 4 b + 16 
Inlocuim in diferenta pe a si obtinem:
4 b + 16 - b = 379 
3 b = 379 - 16 
3 b = 363 
 b = 363 : 3 
 b = 121

a = 4 b + 16 = 4 x 121 + 16 = 484 + 16 = 500

Raspuns:  500,  121