Question

multiply the sum of 6/7 and -13/21 by their difference​

Answer 1

Answer:

155/441

Step-by-step explanation:

lcm = 21

6/7 x 3/3 = 18/21

6/7 = 18/21

Sum:-   6/7 + (-13/21)

           = 18/21 - 13/21

               = 5/21

Difference =  6/7 - (-13/21)          ( - ) x ( - ) = +

                      18/21 + 13/21

                      31/21

Product = 5/21 x 31/21

             = 155/441

Answer 2

$\tiny{\red{\sf{Sum \: of \: Numbers = 6/7+(-13/21)}}}$

$\tiny{\red{\sf{=6/7-13/21}}}$

$\tiny{\red{\sf{=(18-13)/21}}}$

$\tiny{\red{\sf{=5/21}}}$

$\tiny{\red{\sf{Difference \: of \: Numbers =6/7 - (-13/21)}}}$

$\tiny{\red{\sf{=6/7+13/21}}}$

$\tiny{\red{\sf{=(18+13)/21}}}$

$\tiny{\red{\sf{=31/21}}}$

$\tiny{\red{\sf{Product = Sum \: of \: Numbers × Difference \: of \: Numbers}}}$

$\tiny{\red{\sf{=5/21×31/21}}}$

$\tiny{\red{\sf{=155/21}}}$