SOLUTION: fint the value of a in this proportions a/4=9/a

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Question 317301: fint the value of a in this proportions a/4=9/a
Found 2 solutions by nyc_function, jim_thompson5910:
Answer by nyc_function(2741) About Me  (Show Source):
You can put this solution on YOUR website!
a/4 = 9/a
Cross-multiply to find a.
4 * 9 = a * a
36 = a^2
sqrt{36} = sqrt{a^2}
6 = a
Done!

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
a%2F4=9%2Fa Start with the given equation.


a%2Aa=9%2A4 Cross multiply.


a%5E2=36 Multiply.


a=%22%22%2B-sqrt%2836%29 Take the square root of both sides.


a=sqrt%2836%29 or a=-sqrt%2836%29 Break up the plus/minus.


a=6 or a=-6 Take the square root of 36 to get 6.


So the solutions are a=6 or a=-6