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 
In this type of calculations, we decompose 13 by checking the lowest powers of the base, that is 40. for example we check 40^2, or 40^3 and compare it to 85
Notice
40*40*40=64,000
so we check how many time does 85 fit into 64,000:
64,000/85=752.94
85*753=64,005; 64000-64,005=-5
this means that

thus

Answer: 10 (mod85)
Remark, the set of all solutions is:
{......-75, 10, 95, .....}, that is 85k +10
Answer:
x < -20
Step-by-step explanation:
x / -4 + 14 >20
Subtract 14 from each side
x / -4 +14-14 > 20 -14
x / -4 > 6
Multiply each side by -4, remembering to flip the inequality
x / -4 * -4 < 6 * -4
x < -20
Answer:
1/4
Step-by-step explanation:
if you subtract the top, and multiply the bottom, the outcome is 4/16 or 1/4
The answer is 8 + x > 5
An equation or an inequality that contains at least one variable is called an open sentence.
When you substitute the variable in an open sentence with a number the resulting statement is either true or false. If the statement is true the number is a solution to the equation or inequality.
Hope this helps you !!