Question

What is `10/21 -: 18/7`?

Answer 1

See a solution process below:

Explanation:

We can rewrite the expression as:

`(10/21)/(18/7)`

Now, use this rule for dividing fractions:

`(color(red)(a)/color(blue)(b))/(color(green)(c)/color(purple)(d)) = (color(red)(a) xx color(purple)(d))/(color(blue)(b) xx color(green)(c))`

`(color(red)(10)/color(blue)(21))/(color(green)(18)/color(purple)(7)) => (color(red)(10) xx color(purple)(7))/(color(blue)(21) xx color(green)(18)) => (color(red)(2 xx 5) xx color(purple)(7 xx 1))/(color(blue)(7 xx 3) xx color(green)(2 xx 9)) => (color(red)(color(black)(cancel(color(red)(2))) xx 5) xx color(purple)(cancel(color(black)(color(purple)(7))) xx 1))/(color(blue)(color(black)(cancel(color(blue)(7))) xx 3) xx color(green)(color(black)(cancel(color(green)(2))) xx 9)) => (color(red)(5) xx color(purple)(1))/(color(blue)(3) xx color(green)(9)) => 5/27`