<span>A. −6x + 3y = 18 4x − 3y = 6
B 2x + 4y = 24 6x + 12y = 36
C. 3x − y = 14 −9x + 3y = −42
D. 5x + 2y = 13 −x + 4y = −6
For infinitely many solutions, we are looking for linearly dependent equations, which means that one equation is an exact multiple or sub-multiple of the other.
Example:
</span>2x + 4y = 24
6x + 12y = 36
<span>is a system that does NOT have a solution, because 6/2=3 for x, 12/4=3 for y, but 36/24=1.5. The two lines have the same slope (therefore parallel), but they have different y-intercepts. So the two lines will never meet, and therefore no solution.
or another example:
</span> 3x -y = 14
-9x + 3y = -42
We see that -9/3=-3, 3/-1=-3, -42/3=-14, this system has coefficients all in the same ratio, meaning that the lines are coincident (and linearly dependent), therefore infinitely many solutions.
Still another example:
−6x + 3y = 18
4x − 3y = 6
we see that 18/6=3, 3/(-3)=-1 , since the ratios are different, the two equations are not linearly dependent, and therefore the system has unique solution.
Last example:
5x + 2y = 13
−x + 4y = −6
Check the ratio of the coefficients:
-1/5=-1/5
4/2=2 ..... we can stop here and conclude that there is a unique solution because the equations are not in the same ratio. (unique means that there is exactly one solution)
To solve this problem you can apply the proccedure shown below:
1. You have the fexpression given in the problem above, which you can rewrite it as following:
-4√(9/2x)
2. You can find an equivalent expression:
-4√(3²/2x)
(-4)(3)√(1/2x)
-12/√2x
3- If you multiply the numerator and the denominator by √2, you obtain:
(-12√2)/[(√2)²√x]
(-12√2)/(2√x)
(-6√2)/(√x)
Therefore, the answer is:-(-6√2)/(√x)
Answer:
Option C
23.08% markup on selling price.
Step-by-step explanation:
Given in the question,
markup percentage on cost price = 30%
To find,
markup percentage on selling price
Markup is the ratio between the cost of a good or service and its selling price.
Let suppose that cost price percentage = 100%
As we know that,
<h3>cost% + markup% = selling%</h3><h3>100% + 30% = 130%</h3>
So percent markup selling price = 30 / 130 x 100
= 23.0769
Hence, 30% markup on cost price = 23.0769% markup on selling price.
The width of the pathway is 3m
Step-by-step explanation:
Let the width of the pathway be 'w'
The area will be 130 square meters
The dimensions of the garden is 10 x 7
Area = (10+w) (7+w)
130 = 70 + 17w + w^2
w^2 + 17w - 60 = 0
w^2 +20w - 3w - 60 = 0
w ( w + 20) - 3 ( w + 20) = 0
(w + 20) (w - 3) = 0
w = -20 ( or) w = 3
w is the width and cannot be negative.
So, w = 3 meters
The width of the pathway is 3m