You buy books for 64 cents each, you plan to sell them for 75 cents each. You're left with 100 unsold books, and you lost $12. How many books did you sell ?

The number of books sold is 473.

Step-by-step explanation:

The difference between the original price and selling price of the book gives the profit per book.

The profit of one book = Selling price - Original price

Let,

Therefore, the equation is formed as

total Profit = 0.75y - 0.64x

⇒ 0.75y - 0.64x = -12 (1)

Total books = sold books + unsold books

x = y + 100

⇒ x-y = 100  (2)

Substitute x= 100+y in the eq(1),

0.75y - 0.64(100+y) = -12

0.75y - 64 -0.64y = -12

0.11y = -12 +64

y = 52 / 0.11

y = 472.7

y ≅ 473

The number of book sold is 473 books.

The total number of books is (100+473) = 573 books.

step-by-step explanation:

we are given a graph for system of inequalities.

in order to write the system of inequalities for the given graph, we need to find the inequality for each of the line separately.

let us find the slope of dotted line first.

taking two coordinates on the graph.

let us say (0,0) and (3,1).

let us find the slope of the line now.

slope of the dotted line would be =.

y-intercept of dotted line is y=0 only.

plugging slope m= and b=0 in slope-intercept form y=mx+b, we get

.

the line is shaded up of that dotted line.

therefore, for shading up we would take greater than inequality symbol > .

and because it's a dotted line we would take only > symbol in place of = sign in above equation of line.

therefore, inequality for dotted line would be

let us take two points (3,1) and (0,4) on the solid line.

slope of the solid line would be =.

for the solid line we have y-intercept b= 4.

plugging slope m= -1 and b=4 in slope-intercept form y=mx+b, we get

y = -1x + 4.

the line is shaded down of that solid line.

therefore, for shading down we would take less than inequality symbol < .

and because it's a solid line we would take ≤ symbol in place of = sign in above equation of line.

therefore, inequality for solid line would be

x> 6

step-by-step explanation:

8x+8> 7x+14

8x-7x> 14-8

x> 6