Amanda A. answered • 03/23/14
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Dan -
If you're trying to isolate x, the easiest way is to not distribute a in the first equation. This is how I would do it.
If you're trying to isolate x, the easiest way is to not distribute a in the first equation. This is how I would do it.
Original equation: a(x + b) = c
Divide both sides by a: [a(x + b)]/a = c/a
Cancel out a: [a(x + b)]/a = c/a
Simplify: x + b = c/a
Subtract b from both sides: x + b - b = c/a - b
Cancel out b: x = c/a - b
There you go! There's your answer!
Dan M.
or is it because a ( X + B ) is already reduced so you take it from there?
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03/23/14
Amanda A.
You COULD distribute, but you're trying to isolate x, so there's no need to muddy it up by multiplying it by A when you could move the A over to the right side with division.
Where your originally proposed answer fell short was in the simplification. You get here just fine:
Where your originally proposed answer fell short was in the simplification. You get here just fine:
x= (c-ab)/a
But when you simplify, you have to divide both the C and the -AB by the A in the denominator:
But when you simplify, you have to divide both the C and the -AB by the A in the denominator:
x = c/a - ab/a
Which reduces:
x = c/a - ab/a
To give you x = c/a - b.
It just takes more steps if you distribute right away, because you have to undo it on the other side.
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03/23/14
Dan M.
03/23/14