Answer:
a = 10
Step-by-step explanation:
From the solution given, x = a and y = -1
Substitute for x and y in either of the equations
y = -x + 9
-1 = -a + 9
a = 9 + 1 = 10
Answer:
Step-by-step explanation:
It's an integer (which includes the minus number).
It can be a natural number (if the value of an expression comes to +/- 8 and for some reason - 8 is not permitted because it's a length)
It is for certain a real number.
