Question

Daca ab+ac= -52 si b+c= -13, calculati a

Answer 1

AB + AC = -52
B + C = -13

Avem :

Dam factor comun pe numarul A :

A ( B + C ) = -52 - (-32)   --->

A = -52 + 32 = 20    ----->

A = 20

Answer 2

$\displaystyle ab+ac=-52 \\ b+c=-13 \\ a=? \\ ab+ac=-52 \\ a(b+c)=-52 \\ -13a=-52 \\ a= \frac{-52}{-13} \\ a=4$