Answer:
Expression for Perimeter: 6x + 6
x = 12 cm
Verify A = 360:
2(12) x (12+3) = 360
24 x 15 = 360
360 = 360
Step-by-step explanation:
C, a²+b²=c²
why does this have to be 20 characters long
Answer:

Step-by-step explanation:
this is the equation used to find the average of two numbers.
Answer:
x=3, y= -6
Step-by-step explanation:
make 4+y= -x as equation (1) and make y=2x-10 as equation (2, then you must find a third equation either from equation (1)or (2). If you choose to find equation (3) from (2) it will be y=2x-10 , then substitute equation (3) from (1) because you can't choose (2) , then it will be 4+(2x-10)= -x
the answer will be x =2
substitute x from equation (3)
y=2x-10
y=2 (2)-10
y= -6
The answer is C hope this helps