Some algebra I don't understand: Solve for R

[Jaccobtw]

Homework Statement

Solve for R. $$\frac{5}{3} = \frac{0.28 + R}{R}$$

Relevant Equations

Use algebra I guess

The variable is already isolated on one side. I dont' know how to solve for R though. Any help? Thank you.

 

[PeroK]

Homework Statement:: Solve for R. $$\frac{5}{3} = \frac{0.28 + R}{R}$$
Relevant Equations:: Use algebra I guess

The variable is already isolated on one side. I dont' know how to solve for R though. Any help? Thank you.

Fractions are always a problem. Get rid of them!

 

[Jaccobtw]

Fractions are always a problem. Get rid of them!

Ah ok. Multiply both sides by R and then subtract R from both sides. The rest is cake

 

[Mark44]

Ah ok. Multiply both sides by R and then subtract R from both sides. The rest is cake

Better yet, multiply both sides of the equation by 3R, and then isolate the terms with R on one side.

 

[lurflurf]

the difficulty here is R appears twice
we can either merge the R's or eliminate one
to do the later we can...

subtract one from both sides
$$\frac{5}{3} = \frac{0.28 + R}{R}$$
$$\frac{5}{3} -\frac{3}{3}= \frac{0.28 + R}{R}-\frac{R}{R}$$

 

[robphy]

Homework Statement:: Solve for R. $$\frac{5}{3} = \frac{0.28 + R}{R}$$
Relevant Equations:: Use algebra I guess

The variable is already isolated on one side. I dont' know how to solve for R though. Any help? Thank you.

Although R is only on the right-side, I would not describe that R as "isolated".

the difficulty here is R appears twice
we can either merge the R's or eliminate one
to do the later we can...

subtract one from both sides
$$\frac{5}{3} = \frac{0.28 + R}{R}$$
$$\frac{5}{3} -\frac{3}{3}= \frac{0.28 + R}{R}-\frac{R}{R}$$

While true, it may be better to simplify [to reduce the number of R's one sees on]
the right-hand-side by first distributing the [common] denominator, then simplifying further
$$\begin{align*}\frac{5}{3}
&=
\frac{0.28 + R}{R}\\
&=
\frac{0.28}{R} + 1\\
\end{align*}
$$