Answer:
x=3.99 it represents the amount per book
Step-by-step explanation:
3x + 1.50 = 13.47
- 1.50 on both sides
3x= 11.97
Divide 3 on both sides.
x= 3.99
286
588
300
:) your welcome
Answer:
16.2
Step-by-step explanation:
The angle internal to the triangle at B is the supplement of the one shown, so is 65°. That is equal to the angle internal to the triangle at D. Since the vertical angles at C are congruent, the two triangles are similar by the AA theorem.
Corresponding sides of similar triangles are proportional, so we can write the proportion shown in the attachment:
BC/FC = DC/AC
BC = FC(DC/AC) = 21.6(7.2/9.6)
BC = 16.2 . . . . matches the first choice
<h2>
Explanation:</h2>
In every rectangle, the two diagonals have the same length. If a quadrilateral's diagonals have the same length, that doesn't mean it has to be a rectangle, but if a parallelogram's diagonals have the same length, then it's definitely a rectangle.
So first of all, let's prove this is a parallelogram. The basic definition of a parallelogram is that it is a quadrilateral where both pairs of opposite sides are parallel.
So let's name the vertices as:

First pair of opposite sides:
<u>Slope:</u>

Second pair of opposite sides:
<u>Slope:</u>

So in fact this is a parallelogram. The other thing we need to prove is that the diagonals measure the same. Using distance formula:

So the diagonals measure the same, therefore this is a rectangle.