How do you solve for a in #ab + c = d#?

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Answer 1 · 2016-07-07T19:54:48

# a = (d-c)/b#

Remember we can do pretty much anything we like to an equation as long as we do the same to both sides.

Subtract #c# from both sides:

#ab + c color(red)(-c) = d color(red)(-c)#

#therefore ab = d - c#

Divide both sides by #b#

#(ab)/(color(red)(b)) = (d-c)/(color(red)(b))#

#therefore a = (d-c)/b#