For this problem you have yo set up two equations.
White shirts = w Yellow shirts = y
1st: w + y = 21
2nd: 9.95w + 11.50y = 235.30
Now we're going to do system of equations using substitution.
If w + y = 21, then y = 21 - w
If y = 21 - w, then you can substitute this in the second equation for y.
9.95w + 11.50(21 - w) = 235.30
9.95w + 241.5 - 11.50w = 235.30
-1.55w + 241.5 = 235.30
-1.55w = -6.2
w = 4, so 4 whites shirt were sold.
Now I'm finding out how many yellow shirts were sold using one of the two equations at the top.
w + y = 21
4 + y = 21
y = 17
So 17 yellow shirts were sold and 4 white shirts were sold.
The sum(9) of half of the first number(1/2a) and one third of the second number(+1/3b)
That is correct
Answer:
16 cm
Step-by-step explanation:
Suppose that x is the original width. If that original width is enlarged by a scale factor 5/2 that means that x is multiplied by 5/2 and after that multiplication we obtained new width, 40 cm.
Therefore,
x*(5/2) = 40
We multiply the equation by 2 and obtain:
x*5 = 40*2
5x = 80
Now we divide the equation by 5 and obtain:
x = 80/5
x = 16
We obtained that x, the original width was 16 cm
Answer:
The difference of 8 times a number r and 12 is solved for a number r and is given by 
Step-by-step explanation:
Given problem is the difference of 8 times a number r and 12
It can be written as

To simplify the above expression :
8r-12

( using addition property of equality )

(using division property of equality )

Therefore 
Therefore the difference of 8 times a number r and 12 is solved for a number r and is given by 