Answer:
x=1 and y=−2
Step-by-step explanation:
Multiply the first equation by 9,and multiply the second equation by -8.
9(−7x−8y=9)
−8(4x−9y=22)
Becomes:
−63x−72y=81
−32x+72y=−176
Add these equations to eliminate y:
−95x=−95
Then solve−95x=−95for x:
−95x
−95
=
−95
−95
(Divide both sides by -95)
x=1
Now that we've found x let's plug it back in to solve for y.
Write down an original equation:
−7x−8y=9
Substitute1forxin−7x−8y=9:
(−7)(1)−8y=9
−8y−7=9(Simplify both sides of the equation)
−8y−7+7=9+7(Add 7 to both sides)
−8y=16
−8y
−8
=
16
−8
(Divide both sides by -8)
y=−2
Answer:
sqrt(41)
Step-by-step explanation:
Using pythagoras theorem
2. 
Domain:
, because any value of
is allowed and gives a number
.
Range:
, because
for any positive real
.
y-intercept: This is a point of the form
. So plug in
; we get
. So the intercept is (0, 2), or just 2. (Interestingly, you didn't get marked wrong for that...)
Asymptote: This can be deduced from the range; the asymptote is the line
.
Increasing interval: Going from left to right, there is no interval on which
is increasing, since 1/4 is between 0 and 1.
Decreasing interval: Same as the domain;
is decreasing over the entire real line.
End behavior: The range tells you
, and you know
is decreasing over its entire domain. This means that
as
, and
and
.
3. 
Domain: Same as (2),
.
Range: We can rewrite
.
for all
, so
for all
. Then the range is
.
y-intercept: We have
, so the intercept is (0, -6) (or just -6).
Asymptote: 
Increasing interval: Not increasing anywhere
Decreasing interval: 
End behavior: Similar to (2), but this time
as
and
as
.
Answer:
y=6nx-10
y+10=6nx
y+10/6x=n
therefore, n=y+10/6x.
Step-by-step explanation: