How do you solve #\frac { 9} { 10} = \frac { 7} { a }#?

1 Answer
Mar 5, 2018

See a solution process below:

Explanation:

Because both sides of the equation are pure fractions we can "flip" or invert the fractions and not impact the solution:

#10/9 = a/7#

Now, multiply each side of the equation by #color(red)(7)# to solve for #a# while keeping the equation balanced:

#color(red)(7) xx 10/9 = color(red)(7) xx a/7#

#70/9 = cancel(color(red)(7)) xx a/color(red)(cancel(color(black)(7)))#

#70/9 = a#

#a = 70/9#