-6x + y = - 4 / + 6x ;
y = 6x - 4 ;
We substitute y in first equation : -5x + 3( 6x - 4 ) = 12;
-5x + 18x - 12 = 12 ;
13x - 12 = 12 ;
13x = 24 ;
x = 24 / 13 ;
y = 6*(24 / 13 ) - 4 ;
y = 144 / 13 - 4 ;
y = 144 / 13 - 52 / 13;
y = 92 / 13 ;
The solution is x = 24 / 13 and y = 92 / 13 ;
Answer:
Abundance of isotope 79Br=51% and abundance of 81Br=49%
Step-by-step explanation:
We are given that
Mass of 79Br=78.9183 u
Mass of 81Br=80.9163 u
Average atomic mass of bromine=79.90 u
We have to find the relative abundance of the two bromine isotopes.
Let x be the abundance of 79Br
Then , abundance of 81Br isotopes=1-x
Average atomic mass=Mass of isotope(abundance of isotope)+Mass of other isotope(abundance of other isotope)
Using the formula
Percentage of isotope with abundance 0.51=%
Abundance of other isotope=1-0.51=0.49
Percentage of other isotope with abundance 0.49=%
Answer:
40
Step-by-step explanation:
a = 5; b = 9
First, substitute 5 for a and 9 for b.
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So that is what we call a ratio
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