He spent $11 dollars minus tax
Given:
Choose a number between 0 and 20.
If the difference is less than 10 then Eric wins.
Let us x is Eric's number. 0 <u><</u> x <u><</u> 20
If Eric wins. |x -7| < 10
|x-7| < 10 → -10 < x-7 < 10 → -10 + 7 < x - 7 + 7 < 10 + 7 → -3 < x < 17
Taking into account that the number must be given between 0 and 20.
0 <u><</u> x <u><</u> 20
-3 < x < 17
→ 0 < x < 16
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.
49 because you multiply 7x7
