Step-by-step explanation:
Let the numbers are 4x and 7x. According to the question if each number is increased by 20, the ratio becomes 7 : 9.
Then,
( 4x + 20 ) : ( 7x + 20 ) = 7 : 9
9( 4x + 20 ) = 7( 7x + 20 )
9( 4x ) + 9( 20 ) = 7( 7x ) + 7( 20 )
9( 20 ) - 7( 20 ) = 7( 7x ) - 9( 4x )
2( 20 ) = 49x - 36x
40 = 13 x
40 / 13 = x
Therefore, number are :–
4 x = 4( 40 / 13 ) = 160 / 13
7 x = 7( 40 / 13 ) = 280 / 13
The answer to the first question of the attached document is option 1. We obtain the answer subtracting the term n from the series with the term n-1.For example:
-3 - (- 5) = 2
-1 - (- 3) = 2
1 - (- 1) = 2
So you can see that the common difference is the 2.
The answer to the second question is option 3:
y = | x + 7 |
We can confirm it by substituting values in the equation.
For example:
if we do y = 0 then x = -7
if we do x = 0 then y = 7.
As corresponds in the graph shown.
Remember also that as a general rule yes to the equationy = | x | whose vertex is in the point (0,0) we add a positive real number "a" of form y = | x + a | then the graph of y = | x | will move "to" units in the negative direction of x.
The answer to the third question is option 4.
The quotient of x and "and" is constant.
k = y / x
Rewriting:
y = kx
You can see that it corresponds to the equation of a line that passes through the origin, this means that and is proportional to x and both vary directly
Answer would be D You can have a rational discriminant for an irrational root, but you can also have rational discriminant for a rational root. So C is partially correct.
<span>All prime discriminants will result in an irrational root, but not all irrational roots have prime discriminants </span>
The $378.49 was earned on the investment if the principal amount of $3000 is invested for 3 years at 4% compounded semi-annually.
<h3>What is compound interest?</h3>
It is defined as the interest on the principal value or deposit and the interest which is gained on the principal value in the previous year.
We can calculate the compound interest using the below formula:

Where A = Final amount
P = Principal amount
r = annual rate of interest
n = how many times interest is compounded per year
t = How long the money is deposited or borrowed (in years)
Here,
P = $3000
r = 4% = 0.04
n = 2
t = 3 years
After plugging all the values in the formula:

After solving:
A = $3,378.49
I = A - P = 3,378.49 - 3000 = $378.49
Thus, the $378.49 was earned on the investment if the principal amount of $3000 is invested for 3 years at 4% compounded semi-annually.
Learn more about the compound interest here:
brainly.com/question/26457073
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The area of a rectangle is given by its base times its height.
In this case,
