Answer:
its d
Step-by-step explanation:
just took the test
Answer:
sandwich = 6.50
Step-by-step explanation:
Let s = sandwich price
d = drink price
6s + 4d = 53
4s + 6d = 47
Multiply the first equation by 3
18s + 12d = 159
Multiply the second equation by -2
-4s - 12d = -94
Add these equations together
18s + 12d = 159
-8s - 12d = -94
--------------------------
10s = 65
Divide by 10
s = 65/10
s =6.5
Answer:
$42.09
Step-by-step explanation:
1. multiply the cost per gallon (3.45) by the gallons purchased (12.2)
3.45*12.2 = 42.09
Answer:
A=-2
B=-8
Step-by-step explanation:
In order for the system of linear equations to have infinitely many solution, they must be the same equation.
Ax-y=8
2x+y=B
We need to choose A and B so they are the same equation.
I notice they are both in the same form but in the second column you have opposites;
the -y and y.
So im going to multiply either equation by -1 so that part is exactly the same.
Don't choose both; choose only one.
Let's multiply the first equation by -1.
Doing this gives us the following:
-Ax+y=-8
2x+y=B
So now we can choose A and B so these equations appear exactly the same.
We need -A=2 and B=-8.
-A=2 implies A=(opposite of 2) which is -2.
Conclusion:
A=-2
B=-8
Answer:
first get the total ratio; 2 + 5 = 7
so the fraction of blue marbles is 5/7
then assume the number of total marbles to be k
then use the expression;
5/7*k = 65
7*5/7 * k = 65*7
5k =455
5/5k = 455/5
k = 91
then calculate the number if red marbles from;
x = 2/7*91
x = 26
Therefore there are 26 red marbles.
