# pre algebra - solve for b

by Brigitte

Solve for "b"

5b/2/15 = 7/1/5

or

5b÷2÷15 = 7÷1÷5

Before attempting to solve for "b", first simplify the expression on each side of the equation as much as possible.

### Comments for pre algebra - solve for b

 Jan 11, 2011 pre-algebra - equations with fractions by: Staff The question: by Brigitte (Ottawa Ontario Canada) 5b/2/15=7/1/5 The answer: I’m going to assume your problem is stated exactly the way to intended it to be written. I’m going to assume you did not mean something like this: 5b/(2/15)=7/(1/5) With that in mind, I’m going to rewrite this problem to make it a little easier to understand 5b/2/15=7/1/5 5b÷2÷15 = 7÷1÷5 Regardless of the division sequence, the answer will be the same: First, let’s complete the division sequence for 7/1/5 7/1/5 7÷1÷5 7÷1 = 7 7÷5 = 7/5 ∴ 7/1/5 = 7/5 Second, let’s complete the division sequence for 5b/2/15 5b/2/15 5b÷2÷15 5b÷15÷2 5b÷15 = b/3 (b/3)÷2 = (b/3)÷(2/1) (b/3)*(1/2) = (b*1)/(3*2) (b*1)/(3*2) = b/6 ∴ 5b/2/15 = b/6 Third, the solve the equation for the unknown b 5b/2/15=7/1/5 b/6 = 7/5 multiply each side of the equation by 6 6*(b/6) = 6*(7/5) b*(6/6) = 6*(7/5) b*(1) = 6*(7/5) b*1 = 6*(7/5) b = 6*(7/5) b = (6*7)/5 b = (42)/5 b = 42/5 b = 8.4 the final answer is: b = 42/5 (or b = 8.4) Thanks for writing. Staff www.solving-math-problems.com