Solving Proportions by Cross-Multiplication  

✔ StudyForce.com
✔ Biology-Forums...
✔ Ask questions here: Biology-Forums...
To quickly solve proportions, we use a mathematical technique known as cross-multiplication. This method is equivalent to multiplying both sides of the equation by a common denominator, which eliminates the fractions and simplifies finding the unknown value.
Q. Solve each proportion for the unknown variable.
a) 3/17 = x/170
b) 100 : y = 6 : 5.5
c) x/(3/5)=4/(1 1/3)
d) (3 1/9)/(4 5/6)=(2 1/3)/y