Answer:

Step-by-step explanation:
There's a calculated explanation below. I hope this helps!
Answer:
this is for the first one
Answer:
a = 9
Step-by-step explanation:
-6a + 2a = -36
-4a = -36
a = -36/-4
a = 9
If 5.6 and 2.1 are the measurements then:
you multiply 5.6 and 2.1 to get the area.
Area=11.76squared
You add 5.6+5.6+2.1+2.1 to get the perimeter.
Perimeter=15.4