Question

5
a
+ 8
b
+ 8
c
+ 5
d
, ştiind ca
a + b + c
+
d
= 40 si
b + c
= 20.

Answer 1

5a+5d+8b+8c=5[a+d]+8[b+c]=5[a+d]+8·20=5[a+d]+160;
⇒a+b+c+d=40;
⇒a+d=20;
⇒5·20+160
⇒100+160=260;