with a coupon you can get a pair of shoes that normally costs 84$for only 72$ what the amount of money that is the discount​

84 is equal to 100% of the price, and if x is our discount 84x = 72 to find x rearrange the equation so x is alone : x = 72/84 which can be simplified to 6/7 or 0.857. multiplying this by 100 gives the percentage 85.7% which can be simplified to 86% if the answer is only looking for 2 significant figures.

To check the answer is correct you can do 84 x 6/7 = 72

72\84= 0.85
-
0.85* 100= 85.7
-
100-58.7= 14%
-

I think this is the answer

A] the relationship between angles  ∠7 and  ∠8 are defined as vertically opposite angles, they are those angles that opposite to each other when two line cross.  they are vertical in the sense that they share the same vertex (the same corner angles) as opposed to the usual up-down meaning of vertical. 

b] the angles created by this intersection between c and d are special because they are equal to each other, to solve for y we shall have:
(5y-29)=(3y+19)
this is because they are vertical angles, hence solving the above we get:
5y-3y=19+29
2y=48
y=48/2
y=24°

c] to solve for  ∠7 and  ∠8 we proceed as follows;
angles in a straight line add up to 180:
therefore:
(5y-29)+∠7=180
substituting the value of y in the above and solving for  ∠7 we get:
(5×24-29)+∠7=180
91+∠7=180
∠7=180-91
∠7=89

but remember that  vertical angles are equal to each other, therefore:
∠7=∠8=89°