In the following shape, two semicircles
1 answer:
Answer:
The length around the figure in terms of r is 2r ( + 4).
Step-by-step explanation:
The perimeter of an object is the total length of the boundary of the object.
The figure consists two similar semicircle and a rectangle.
Adding the two semicircles, a complete circle is formed. The circumference of a circle = 2r.
The rectangle has a length which is twice its height.
i.e l = 2h
But,
r = (the diameters of the semicircles equal the height of the rectangle)
⇒ h = 2r
Thus, one side length of rectangle = 2 × 2r (l = 2 × h)
= 4r
The length around the figure in terms of r is:
= 2r + 4r + 4r
= 2r + 8r
= 2r ( + 4)
The length around the figure in terms of r is 2r ( + 4).
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Answer:
(negative 7 x + 4)(negative 7 x minus 4)
Step-by-step explanation:
Consider two real numbers a and b. A difference of squares involving a and b is usually given as;
The difference of the two squares above can be factored to yield;
This implies that in order to have the difference of squares we must have a product involving the difference and the sum of the numbers.
The expression;
(negative 7 x + 4)(negative 7 x minus 4) can also be written as ( 4 - 7x) ( -4 - 7x)
( 4 - 7x) ( -4 - 7x) = ( 4 - 7x) (-1( 4 + 7x)) = -1 *( 4 - 7x) ( 4 + 7x)
Expanding the last expression yields;
-1 (16 + 28x -28x - 49x^2) = -1 (16 - 49x^2) = 49x^2 - 16 which is in deed a difference of squares