Answer:
3 is the missing answer.
Step-by-step explanation:
7 * 3 = ( _ * 3) + ( 4 * 3)
21 = ( _ * 3) + 12 -Multiply 4 * 3 and 7 * 3
9 = _ * 3 -Divide both sides by 3
3 = missing number
The equivalent expression to 
<h3>What are the equivalent expressions?</h3>
Equivalent expressions are similar expressions that may have different forms but when a value is replaced with the variables in the same form provides the same answer.
From the information given, If:
- r(x) = 3x - 1
- s(x) = 2x + 1
Then the fractional form can be an expression as:

where;



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The surface area of hemisphere is given by:

Where r is radius of hemisphere.
We are given diameter = 250 ft.
We know that radius = half of diameter.
Radius of dome = 1/2 (250) = 125 ft.
Now let us plug the value of radius in the formula,

Surface Area of dome = 98125 square foot.
<h3>
Answer:</h3>
- C. (9x -1)(x +4) = 9x² +35x -4
- B. 480
- A. P(t) = 4(1.019)^t
Step-by-step explanation:
1. See the attachment for the filled-in diagram. Adding the contents of the figure gives the sum at the bottom, matching selection C.
2. If we let "d" represent the length of the second volyage, then the total length of the two voyages is ...
... (d+43) + d = 1003
... 2d = 960 . . . . . . . subtract 43
... d = 480 . . . . . . . . divide by 2
The second voyage lasted 480 days.
3. 1.9% - 1.9/100 = 0.019. Adding this fraction to the original means the original is multiplied by 1 +0.019 = 1.019. Doing this multiplication each year for t years means the multiplier is (1.019)^t.
Since the starting value (in 1975) is 4 (billion), the population t years after that is ...
... P(t) = 4(1.019)^t