<h3>
Answer:</h3>
42. 29°
43. 3x³ +2x² -3x +10
44. 20a² +68a
<h3>
Step-by-step explanation:</h3>
42. The right-angle corner tells you the two marked angles are complementary — they sum to 90°.
(-3x +20)° + (-2x +55)° = 90°
-5x +75 = 90 . . . . . . . . . . collect terms, divide by °
-5x = 15 . . . . . . . . . . . . . . . subtract 75
x = -3 . . . . . divide by the coefficient of x
The angle of interest is (-3x+20)°. Filling in the found value for x, we have ...
(-3·(-3) +20)° = 29° = m∠BDC
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43. The distributive property is useful for multiplying polynomials.
(x +2)(3x² -4x +5) = x(3x² -4x +5) +2(3x² -4x +5)
= 3x³ -4x² +5x +6x² -8x +10 . . . . . eliminate parentheses
= 3x³ +2x² -3x +10
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44. Area is the product of length and width, so this becomes a problem in multiplying polynomials.
area = (5a +17)(4a) = 20a² +68a . . . . area in square feet
The expression will look like this. (3*6)+4
Answer:
The sum of the arithmetic sequence is
.
Step-by-step explanation:
A sequence is a set of numbers that are in order.
In an arithmetic sequence the difference between one term and the next is a constant. In other words, we just add the same value each time infinitely.
If the first term of an arithmetic sequence is
and the common difference is d, then the nth term of the sequence is given by:

For the sequence

The pattern is continued by adding -11 to the last number each time.
An arithmetic series is the sum of an arithmetic sequence. We find the sum by adding the first,
and last term,
, divide by 2 in order to get the mean of the two values and then multiply by the number of values, <em>n</em>
<em> </em>
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The sum of the arithmetic sequence is

