Answer:
a = -10
Step-by-step explanation:
-0.4a + 3 = 7
subtract 3 from each side
-0.4a + 3-3 = 7-3
-.4a = 4
Divide each side by -.4
-.4a/ -.4 = 4/-.4
a = - 10
Answer: Option D.
Step-by-step explanation:
You can calculate the surface area of this right prism by adding the area of its faces.
You can observe that the faces of the right prism are: Three different rectangles and two equal triangles.
The formula for calculate the area of a rectangle is:

Where "l" is the lenght and "w" is the width.
The formula for calculate the area of a triangle is:

Where "b" is the base and "h" is the height.
You can observe that the hypotenuse of the each triangle is the width of one of the larger rectangle, then , you can find its value with the Pythagorean Theorem:

Where "a" is the hypotenuse and "b" and "c" are the legs of the triangle.
Then, this is:

Therefore, you can add the areas of the faces to find the surface area of the right prism (Since the triangles are equal, you can multiply the area of one of them by 2). This is:

Answer:
11.7
Step-by-step explanation:
multiply RS by the scale factor to get R'S'
Answer:
║

[Corresponding Sides of similar triangles are proportional.]

Answer:
4
Step-by-step explanation:
one person is deemed to drive and that person is fixed on the driver's seat no mater which arrangement.
we have now 2 more seats one adjacent to the driver and one rear (two combined).
so the total ways in which all five can be arranged is as follows.
driver, adjacent to him(1) and three back.
driver adjacent to him (different person) and three back.
see the driver is always fixed so we can ignore him.
thus we when driver set fixed , on two remaining seats (adjacent to driver and the back )there can be 4 different combinations.