Question

verify a+b = b+a 1•) a = 2/-7 , b = 4/-21​

Answer 1

$a + b = b + a \\ \frac{2}{ - 7} + \frac{4}{ - 21} = \frac{4}{ - 21} + \frac{2}{ - 7} \\ \frac{6 + 4}{ - 21} = \frac{4 + 6}{ - 21} \\ 10 = 10$

Proved

Answer 2

Step-by-step explanation:

a+b=b+a

−7

2

+

−21

4

=

−21

4

+

−7

2

−21

6+4

=

−21

4+6

10=10