#### Answer

a. yes
b. no

#### Work Step by Step

To find out if an ordered pair is a solution you need to insert the values of the variables into the equation. If the answer of the system is true, the pair is a solution, if not it isn't.
a. $2\times-2-3\times-4=8<=>8=8$
$-2-2\times-4=6<=>6=6$
b. $2\times7-3\times2=8<=>8=8$
$7-2\times2=6<=>3\ne6$