Question

Daca x=3 si y+z=10,calculeaza:
a)7·x+7·y+7·z
b)17·x+17·y+17·z-10
c)5·x+10·y+10·z
d)100·x-(9·y+9·z)
Dau coroana!!URGENT!!!!!

Answer 1

a) 7·x+7·y+7·z =
= 7×(X + Y + Z) =
= 7× (3 + 10) =
= 7 × 13 =
= 91

b) 17·x+17·y+17·z-10 =
= 17 × (X +Y + Z) - 10 =
= 17 × (3 + 10) - 10 =
= 17 × 13 - 10 =
= 221 - 10 =
= 211

c) 5·x+10·y+10·z =
= 5 × ( X + 2Y + 2Z) =
= 5 × [ 3 + 2(Y +Z)] =
= 5 × ( 3 + 2 × 10) =
= 5 × 23 =
= 115

d) 100·x-(9·y+9·z) =
= 100 × 3 - 9 × (Y +Z) =
= 300 - 9 × 10 =
= 300 - 90 =
= 210