Jennifer used 2/7 of meter of ribbon to make bows for the her cousins. now she has 10/21 of meter of ribbon left

Jennifer used : 2/7.

Remaining length of the ribbon = 10/21.

Total length of the ribbon in starting = Length of used ribbon + Remaining length of the ribbon .

Therefore,

Total length of the ribbon in starting =  2/7 +10/21

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b