The discussion focuses on rearranging the formula 10b + 5be - 3e + 7c to make e the subject. The correct rearrangement is e = (7c - 10b) / (5b - 3), emphasizing the necessity of using parentheses for clarity. Participants confirm that the initial equation must be properly defined for accurate manipulation. The conversation highlights the importance of starting with a valid equation to derive the correct expression for e.
PREREQUISITESStudents learning algebra, educators teaching mathematical concepts, and anyone looking to improve their skills in rearranging equations.
You're not starting with an equation! Without the first line below being an equation, you can't solve for anything.Gringo123 said:I need to rearrange this formula to make e the subject. Have I done it correctly?
Assuming that this is your starting equation -- 10b + 5be - 3e = 7c -- your work following it is fine, EXCEPT that you need to use parentheses. You should write e this way:Gringo123 said:10b + 5be - 3e + 7c
10b + 5be - 3e = 7c
5be - 3e = 7c - 10b
e(5b - 3) = 7c - 10b
e = 7c - 10b / 5b - 3
Mark44 said:You're not starting with an equation! Without the first line below being an equation, you can't solve for anything.
Assuming that this is your starting equation -- 10b + 5be - 3e = 7c -- your work following it is fine, EXCEPT that you need to use parentheses. You should write e this way:
e = (7c - 10b) / (5b - 3)