Question

How do you solve 6/15=2/c

Answer 1

You cross multiply so you get 15 x 2= 6 x c
this is 30= 6c. if you divide both sides by 6 you get c =5

Answer 2

Solve

$\mathsf{\dfrac{6}{15}=\dfrac{2}{c}}$


Multiplying both sides by 15:

$\mathsf{\diagup\!\!\!\!\! 15\cdot \dfrac{6}{\diagup\!\!\!\!\! 15}=15\cdot \dfrac{2}{c}}\\\\\\ \mathsf{6=\dfrac{30}{c}}$


Since $\mathsf{c}$ is a denominator of a fraction, it can't be zero. Then, you can also multiply both sides by $\mathsf{c}:$

$\mathsf{6\cdot c=\dfrac{30}{\diagup\!\!\!\! c}\cdot \diagup\!\!\!\! c}\\\\\\ \mathsf{6\cdot c=30}\\\\\\ \mathsf{c=\dfrac{30}{6}}\\\\\\ \boxed{\begin{array}{l} \mathsf{c=5} \end{array}}\qquad\checkmark$


Cross-multiplication works fine as well and you would get to the same result.


I hope this helps. :-)