For #6
x + y = -10
x - y = 2
First solve for y in one of the equations
x - y = 2
-y = 2 - x
y = -2 + x
y = x - 2
Now substitute into one of the equations and solve for x
x + y = -10
x + x - 2 = -10
2x - 2 = -10
2x = -8
x = -4
Answer:
Step-by-step explanation:
Given the approximate demand function of night drink expressed as;
p^2+200q^2=177,
p is the price (in dollars) and;
q is the quantity demanded (in thousands).
Given
p = $7
q = 800
Required
dq/dp
Differentiating the function implicitly with respect to p shown;
2p + 400d dq/dp = 0
400q dq/dp = -2p
200qdq/dp = -p
dq/dp = -p/100q
substitute p and q into the resulting equation;
dq/dp = -7/100(800)
dq/dp = -7/80000
dq/dp = -0.0000875
This means that the rate of change of quantity demanded with respect to the price is -0.0000875
Answer:
3 days
Step-by-step explanation:
The problem statement tells you that Kelly is there for 3 days.
Answer:
y = 3
x = 2
Step-by-step explanation:
-5x + 4y = 2
9x - 4y = 6
Sum both eq.
-5x + 9x = 4x
+4y - 4y = 0
2 + 6 = 8
then:
4x + 0 = 8
4x = 8
x = 8/4
x = 2
from the first eq.
-5x + 4y = 2
-5*2 + 4y = 2
-10 + 4y = 2
4y = 2 + 10
4y = 12
y = 12/4
y = 3
Check:
from the second eq.
9x - 4y = 6
9*2 - 4*3 = 6
18 - 12 = 6
Answer:
because its 5 units to the left on a horizontal number line
