Answer:
1/7
Step-by-step explanation:
Since we do not know the number let us use the alphabet A to represent the unknown number
A × 1/3= 1/21
A/3= 1/21
Cross multiply both sides
A×21= 3×1
21A= 3
Divide both sides by the coefficient of A which is 21
21A/21=3/21
A=1/7
Hence the unknown number is 1/7
If it is the most common isotope and of Carbon and it is not an ion, you can conclude that it has 6 protons and 6 electrons.
Answer:
90 degrees
Step-by-step explanation:
If two angles are supplementary they are a linear pair which means they form a straight line, and if you know a straight line equals 180 degrees which is the total degrees of a triangle.
Now if you have two supplementary angles and they are congruent that means not only are they right angles but its half of 180 so you divide these pair of 2 by 180 giving you your total of 90 degrees.
Have a nice rest of your day !
