Question

17x+14y=146
14x+17y=164
par adding equation 1&2
31(x+y)=310
x+y=10
equation 2&1
17x+14y=164
-14x-17y=-146
3x-3y=18
3(x-y)=18
x-y=6
x+y=10
2x=16
x=8
3x=3×8=24​

Answer 1

Answer:

Valency of first 20 elements is given below.

Valency of first 20 elements is given below.Hydrogen (H) = 1.Helium (He) = 0.Lithium (Li) = 1.Beryllium (Be) = 2.Boron (B) = 3.Carbon (C) = 4.Nitrogen (N) = 3.Oxygen (O) = 2.