The answer is 126 because you multiply 6 times 4 which equals 24 and subtract that from 150 so 150-24 = 126
Let cost of 1 box of red pen = x
Let cost of 1 box of black pen = y
Gaga bought 5 red box and her sister 4 black box then total cost is given by
5x+4y
Given that total cost was $44
so equation will be 5x+4y=44...(i)
After exchange
Gaga= 4 red box + 1 Black box
Sister = 1 red box + 3 Black box
then cost for Gaga = 4x+1y
cost for sister = 1x+3y
Given that cost for both after exchange is same so we get
4x+1y = 1x+3y
or 4x-1x = 3y-1y
or 3x = 2y
or 3x/2=y ...(ii)
plug (ii) into (i)
5x+4y=44
5x+4(3x/2)=44
5x+12x/2=44
5x+6x=44
11x=44
x=4
Now plug value of x into (ii)
y=3x/2=3*4/2=12/2=6
Hence cost of 1 box of red pen = $4
And cost of 1 box of black pen = $6
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If you want to get solution without solving both equations then just graph both equations and find the intersection point.
You will see that graph intersect at (4,6) which gives x=4, y=6
To do this problem, you will need to know the side lengths of the triangle. If you have those, just plug them in for a, b, and c and evaluate the square root.
Here is an example. If the sides are 3, 4, 5.
It would be:

The 6 is in the formula because it is the semi-perimeter (half).
Answer:
Y=x+6
Step-by-step explanation:
Answer:
Loan Amount= $4500
Monthly Payment= $600
9 months= $600*9= $5400
Interest = $5400-$4500= $900