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.
This is a linear equation
y=mx+b
y=50x+400 (when x equals the number of hours played)
1000=50x+400
*first, isolate the variable (x)
-50x=-1000+400
*divide by -50 to get x by itself
x=20+8
The answer is x=28
The answer would be w= 7z/2 Isolate the variable but dividing each side by factors that don’t contain the variable
Here's the rule for working with these things:
There are 3 signs associated with a fraction:
=> the sign of the numerator
=> the sign of the denominator
=> the sign of the whole fraction; (if the fraction were in
parentheses, this sign would be written outside).
-- You can change any 2 of them without changing the value of the fraction.
-- Changing any 1 of them changes the effective sign.
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Now, you said the fraction is negative.
So, let's start with the positive fraction, and see the different ways
that we could make it a negative fraction:
=> mark only the numerator negative
=> mark only the denominator negative
=> put parentheses around the fraction, and mark it negative outside
If you do any one of these things to a normal positive fraction,
it turns into a negative fraction.
Look at the choices you listed in the question:
-- in the numerator only ? Yes. That makes it a negative fraction.
-- in the denominator only ? Yes. That makes it a negative fraction.
-- both ? No. That makes it the same as a positive fraction.
-- put parentheses around the fraction, and a negative sign outside ?
Yes. This makes it a negative fraction.
-- it doesn't matter ? No. I hope you can see that it does matter.
Have I confused you ?
Is this more than you wanted to know ?
