Since sales tax goes after the discount, it would be 3 dollars and 20 cents. Taking 50 dollars and 20% is discounted (50*.2), which would be 10 dollars taken off. It would be 40 dollars shoes and then you apply sales tax by multiplying 40 by .08, giving you the amount of tax paid.
Number 5 is 22 and 35
For example: 7+1=8, 8+2 =10, 10+3=13, 13+4=17, 17+5=22, 22+6=28, 28+7=35
Mine is pretty rough but hope it helps look at the attached image.
Rewrite the boundary lines <em>y</em> = -1 - <em>x</em> and <em>y</em> = <em>x</em> - 1 as functions of <em>y </em>:
<em>y</em> = -1 - <em>x</em> ==> <em>x</em> = -1 - <em>y</em>
<em>y</em> = <em>x</em> - 1 ==> <em>x</em> = 1 + <em>y</em>
So if we let <em>x</em> range between these two lines, we need to let <em>y</em> vary between the point where these lines intersect, and the line <em>y</em> = 1.
This means the area is given by the integral,

The integral with respect to <em>x</em> is trivial:

For the remaining integral, integrate term-by-term to get

Alternatively, the triangle can be said to have a base of length 4 (the distance from (-2, 1) to (2, 1)) and a height of length 2 (the distance from the line <em>y</em> = 1 and (0, -1)), so its area is 1/2*4*2 = 4.