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put this solution on YOUR website!(a+b)/2 = 10 (first equation)
(b+10)/2 = (c/2) (second equation)
first equation states that the average of a and b is 10.
second equation states that the average of b and 10 is c/2
question is what is the average of a and c.
take the second equation and solve for b.
second equation is:
(b+10)/2 = c/2
multiply both sides of this equation by 2 to get:
b + 10 = c
subtract 10 from both sides of this equation to get:
b = c - 10
substitute for b in the first equation.
first equation is:
(a+b)/2 = 10
multiply both sides of this equation by 2 to get:
a + b = 20
subsstitute (c-10) for b to get:
a + c - 10 = 20
add 10 to both sides of this equation to get:
a + c = 30
divide both sides of this equation by 2 to get:
(a+c)/2 = 15
average of (a+c) is equal to 15.
