Y = -x + 4.....so sub in -x + 4 in for y in the other equation
x + 2y = -8
x + 2(-x + 4) = -8
x - 2x + 8 = -8
x - 2x = -8 - 8
-x = -16
x = 16
y = -x + 4
y = -16 + 4
y = - 12
one solution (16,-12)
Answer:


Step-by-step explanation:
Given

Solving (a): 
We have:

Express f(x) as y

Swap x and y

Add 8 to 


Square both sides

Rewrite as:

Express y as: 

To determine the domain, we have:
The original function is 
The range of this is: 
The
of the
function is the
of the
function.
<em>Hence, the domain is:</em>

Answer:
i also dont know
Step-by-step explanation:
im also in grade7 answering math
Answer:
The tax rate is 4.3%
Step-by-step explanation:
First, we have to assume $2.79 is 100%. We know that x% equals 0.12 of the output value. Now we have two simple equations: 100%=2.79 and x%=0.12.
Then, 100%/x%=2.27/0.12 and that gives us 4.3%!
Hope this helps.