Answer:
Option C
The student's conclusion is correct because the solution to the system of equations
and
is 
Step-by-step explanation:
Let
x------> the cost of each burger
y-----> the cost of each sandwich
we know that
-----> equation A
----> equation B
Solve the system of equations
Multiply the equation B by 
----->
------> equation C
Adds equation A and equation C

Substitute the value of x in the equation B



The solution of the system of equations is the point 
so
The price of each burger is 
The price of each sandwich is 
Answer: It's C.
Step-by-step explanation:
Answer:
-6
Step-by-step explanation:
7k − 5k + 8 = −4
2k+8=-4
-8 -8
2k=-12
/2 /2
k=-6
<u><em>Check!</em></u>
7(-6)-5(-6)+8
-4=-4
Cot x = cos x / sin x
cot π/4 = cot 45° = cos 45° / sin 45°
We know that sin 45° and sin 45° have the same value:
cos 45° = sin 45° = √2 / 2;
cos 45° / sin 45° = √2/2 : √2/2 = 1
Answer:
cot π/4 = 1