Let x be the number of pounds of the $1.35 beans. The cost of those beans is $1.35 * x, or 1.35x.
<span>Let y be the number of pounds of the $1.05 beans. The cost of those beans is $1.05 * y, or 1.05y. </span>
<span>We know that 120 pounds of the mix sells for $1.15/pound, for a total of 120 * 1.15 = $138. </span>
<span>x + y = 120 </span>
<span>1.35(x) + (1.05)y = 138 </span>
<span>We can rewrite the first as </span>
<span>x = -y + 120 </span>
<span>Now we can substitute (-y + 120) in for (x) in the second equation, because we just proved they're equal. </span>
<span>1.35(x) + 1.05(y) = 138 </span>
<span>1.35(-y + 120) + 1.05y = 138 </span>
<span>-1.35y + 162 + 1.05y = 138 </span>
<span>-0.3y + 162 = 138 </span>
<span>-0.3y = -24 </span>
<span>y = 80 </span>
<span>And since x + y = 120, that means x = 40. </span>
<span>Check: </span>
<span>40 pounds of x at $1.35 costs 40 * 1.35, or $54. </span>
<span>80 pounds of y at $1.05 costs 80 * 1.05, or $84. </span>
<span>Do those add up to our target total, according to the question, of 120 * 1.15 = $138? </span>
This question is incomplete because the options are missing. Here are the options:
A. - 4 = 5x
B. -4 = x
C. -4 + x = 0
D. -4 + 5x = 0
The correct next line of the solution is A. -4 = 5x
An equation is:
- A mathematical expression that represents mathematical equality between two expressions.
- It has two expressions and is separated by the equal sign, called members.
- It has known elements and unknown or unknown data represented with letters like x
According to the above, it can be inferred that the correct answer is option A. because it expresses the correct values according to the operations that have been carried out in the previous lines.
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Answer:
B) consistent, dependent
Step-by-step explanation:
The given system is
45x - 30y = -90
-12x + 8y = 24
Let us make y the subject in both equations to get:
Top equation

Bottom equation

We can see that both equations are identically the same.
There is going to be infinitely many solutions.
We say the system is consistent and dependent.
The correct choice is B
4n² - 16n - 84 = 0
Multiply both sides by 1/4 :
n² - 4n - 21 = 0
Add 21 to both sides:
n² - 4n = 21
Complete the square by adding 4 to both sides:
n² - 4n + 4 = 25
(n - 2)² = 25
Solve for n :
n - 2 = ± √25
n - 2 = ± 5
n = 2 ± 5
Then n = 2 + 5 = 7 or n = 2 - 5 = -3.