Adam and barb had a used book sale over the weekend. adam sold 4 hardcover books and ten paperbacks and earned $64 for his efforts. barb sold 5 hardcover books and 7 paperbacks for the same prices each. barb made $58. adam and barb both charged the same price for the hardcover books and the same price for the paperbacks. how much did they charge for hardcovers and how much for paperbacks? show your work.

Let us suppose they charge $x for hardcover books and $y for  paperbacks..

According to question:

4x+10y=641 and

5x+7y=582

We have a linear equations with two variables.We can use Elimination method to solve for x and y.Multiplying equation 1 by 5 and equation 2 by 4 we have:

20x+50y=320.

10x+28y=232

-       -      -

22y =88

Dividing both sides by 22 y=4.

we replace variable y in the first equation :

4x+10*4=64

4x+40=64.

Subtracting 40 both sides:

4x=24

Dividing by 4 both sides x=6.

Total charge for hardcovers is 5x+4x=9x=9x6=$54.

Total charge for paperbacks is =7y+10y=17y=17(4)=$68.

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3

29933333.33

step-by-step explanation: