Question

What should be subtracted from (3/7+4/21)be subtracted to get 5/6

Answer 1

let the no. subtracted be x

5/6 = (3/7 + 4/21) - x (rationalising the denominator)

5/6 = (9/21 + 4/21) - x

5/6 = 13/21 - x

x = 13/21 - 5/6 (rationalising the denominator)

x = 26/42 - 35/42

x = -9/42

x = -3/14

Answer 2

Answer:

-3/14

Step-by-step explanation:

let the no. subtracted be x

5/6 = (3/7 + 4/21) - x (rationalising the denominator)

5/6 = (9/21 + 4/21) - x

5/6 = 13/21 - x

x = 13/21 - 5/6 (rationalising the denominator)

x = 26/42 - 35/42

x = -9/42

x = -3/14