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 
Hey there mate!
Please check the attached answer of picture for explanation.
On the right side, there are
• 2•2 = 4 atoms of Nb
• 2•5 = 10 atoms of O
so among the reactants on the left, the reaction is balanced as
4 Nb + 5 O₂ → 2 Nb₂O₅
If b is in the first position then c can be in any 1 of the remaining 6 positions.
If we start with ab then the letter c can be in any one of 5 positions and if we have aab there are 4 possible positions for c and so on.
So the total number of possible sequences where b comes first = 6+5+4+3+2+1 = 21.
The same argument applies when c comes before b so that gives us 21 ways also.
So the answer is 2 *21 = 42 different sequences.
A more direct way of doing this is to use factorials:-
answer = 7! / 5! = 7 * 6 = 42.
( We divide by 5! because of the 5 a's.)
Answer:
b. -1
Step-by-step explanation:
9=4a+13
-13 -13
--------------
-4=4a
4a/-4
a=-1
