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Expert: Sherry Wallin - 9/1/2010


Question
the area of a trapezoid is A=(a+b)hdivided by 2 ifA=300,h=5andb=30 what is the value of a

Answer
Oscar~

All you have to do is out in the numbers for each of the letters. Just put in A = 300 for the A in the formula and 5 for the h and 30 for the b and then solve for a:

300 =(a+30)5/2 ->
2*300 = [(a+30)5*2]/2 -> since you are dividing by 2 you need to  
                        multiply both sides by 2
600 = (a+30)5 ---------> simplify
600/5 = (a+30)5/5 -----> divide both sides by 5
120 = a+30 ------------> simplify
120-30 = a + 30 - 30 --> subtract 30 from both sides
90 = a ----------------> simplify

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Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

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