Question

Media aritmetica a numerelor 4a; 7a; 3a si 20 este 40. Aflati a

Answer 1

$\frac{4a+7a+3a+20}{4}$=40 => $\frac{14a+20}{4}$=40 => 14a+20=160 => 14a=140 => a=10

Answer 2

(4a+7a+3a+20)/4= 40 =>
=> 14a+20= 40*4 =>
=> 14a+20= 160 =>
=> 14a= 160-20 =>
=> 14a= 140 =>
=> a= 140/14 =>
=> a= 10