Answer: 4. (-1,-1) 3. (3,-2)
4)
Set the equations equal to each other.
4x+3=-x-2
Subtract 3 from both sides
4x=-x-5
Add x to both sides
5x=-5
Divide both sides by 5
x=-1
Next, replace x with -1 in either equation to find y.
-(-1)-2=y
-1=y
3)
Do the same thing for this one and set them equal to each other
-2x+4=-1/3x-1
Add 1 to both sides
-2x+5=-1/3x
Add 2x to both sides
5=5/3x
Divide both sides by 5/3
x=3
Next, replace x with 3 in either equation
-2(3)+4=y
-2=y
There are 10 letters in the set {a, b, c, d, e, f, g, h, i, j} which is the pool of letters to choose from when making these three letter codes.
We have 10 choices for slot 1
Then 9 choices for slot 2. This is because we can't reuse the choice for slot 1
Then 8 choices for slot 3
Overall, there are 10*9*8 = 90*8 = 720 different permutations
Answer: 720
Note: you can use the nPr permutation formula with n = 10 and r = 3 to get the same answer
On month -------- 10%
12 month ---------- x %
-------------------------------
x = 12*10/1 = 12*10 = 120%
To solve this problem, we must first find the discount amount, and then subtract this amount from the total price of the item.
To find the discount amount, we must find 35% of $40. To do this, we must first convert 35% to its decimal equivalent by dividing 35/100. We do this because percentages are parts out of a total 100 percent, thus this fraction represents an equivalent value that we can multiply by other numbers. Using our knowledge that 35/100 = 0.35, we can now set up our expression:
35% of $40 (keep in mind that the word "of" refers to multiplication in math)
0.35 * 40
To solve, we just multiply these two numbers together, which gives us 14.
This means that Kala got a discount of $14 off of the original price of $40. To find out how much she paid for it, we must subtract $14 from $40, as modeled below:
$40 - $14 = $26
Therefore, Kala paid $26 for the item.
Hope this helps!
Call the notebooks x, and the pencils y.
<span>3x + 4y = $8.50 and 5x + 8y = $14.50 </span>
<span>Then just solve as simultaneous equations: </span>
<span>3x + 4y = $8.50 </span>
<span>5x + 8y = $14.50 </span>
<span>5(3x + 4y = 8.5) </span>
<span>3(5x + 8y = 14.5) </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 24y = 43.5 </span>
<span>Think: DASS (Different Add, Similar Subtract). 15x appears in both equations so subtract one equation from the other. Eassier to subtract (15x + 20y = 42.5) from (15x + 24y = 43.5) </span>
<span>(15x + 24y = 43.5) - (15x + 20y = 42.5) = (4y = 1) which means y = 0.25. </span>
<span>Then substitue into equation : </span>
<span>15x + 20y = 42.5 </span>
<span>15x + 5 + 42.5 </span>
<span>15x = 42.5 - 5 = 37.5 </span>
<span>15x = 37.5 </span>
<span>x = 2.5 </span>
<span>15x + 24y = 43.5 </span>
<span>15(2.5) + 24(0.25) </span>
<span>37.5 + 6 = 43.5 </span>
<span>So x (notebooks) are 2.5 ($2.50) each and y (pencils) are 0.25 ($0.25) each.</span>
