Question 135983
Hope I have the right section here, I have multiple variables... The equation I'm needing help with is: 
.75 = a/(a + v)
Solve for v 


First, lets multiply each side by (a+v).  That will get rid of the fraction

0.75(a+v)=a(a+v)/(a+v) and this equals
0.75(a+v)=a now get rid of the parens (distributive law)
0.75a+0.75v=a  subtract 0.75a from each side

0.75a-0.75a+0.75v=a-0.75a  collect like terms

0.75v=0.25a  divide each side by 0.75
v=0.25a/0.75 and this equals(1/3)a

therefore
v=(1/3)a

CK
0.75= a/(a+(1/3)a)
0.75=a/(4/3)a 
0.75=1/(4/3) multiply the numerator and denominator of the right side by 3/4
0.75=(3/4)/1 or 3/4
0.75=0.75


Hope this helps---ptaylor