SOLUTION: Good Evening Tutor, I have a question from a question in the textbook. The area of a triangle is A=1/2bh. My question asks: Solve each literal equation for the indicat

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Good Evening Tutor, I have a question from a question in the textbook. The area of a triangle is A=1/2bh. My question asks: Solve each literal equation for the indicat      Log On


   

Question 87578This question is from textbook Beginning Algebra
: Good Evening Tutor,
I have a question from a question in the textbook. The area of a triangle is
A=1/2bh.
My question asks: Solve each literal equation for the indicated variable.
I am solving (for b) the area of a trapezoid and the equation is
A=1/2h (B+b)
I am unsure how to change the equation to find b can you please explain to me what equation to use and why? I am sure that B+b will be the lengths of the 2 parallel sides but I am unsure how to get to the answer. Thank you greatly for your help. This question is from textbook Beginning Algebra

Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
A=%281%2F2%29h+%28B%2Bb%29+ From the beginning notice that B and b represent different variables!

Start by clearing the fraction. Multiply both sides by 2.
2A+=+2%281%2F2%29h%28B%2Bb%29
2A+=+h%28B%2Bb%29

Next, use the distributive property to remove the parentheses:
2A+=+Bh+%2Bbh+

Next, you must isolate the b term. Subtract Bh from each side.
2A+-Bh+=+Bh-Bh+%2Bbh
2A+-Bh+=+bh

Finally, you need to get the "b" by itself, so you need to "undo" the "h" that is multiplied times the "b". Because the operation is multiplication, you will need to DIVIDE both sides by h.
%282A+-Bh%29%2Fh=+%28bh%29%2Fh
%282A-Bh%29%2Fh+=+b

I should have a lesson plan in algebra.com on Literal Equations. Also, check my own website by clicking on my tutor name anywhere in algebra.com. Go to MATH IN LIVING COLOR, and look in Intermediate Algebra, in Section 1.04 and also Section 2.07.

R^2 Retired from SCC