Answer:
See explanation
Step-by-step explanation:
<u><em>1st photo:</em></u>
x =

= 15
x =
<u><em>2nd photo:</em></u>
(a) GEH ~ FGH ~ FEG
<em>similar triangles, use similar corners in the right order</em>
(b)
AND 
<em>similar triangles, use similar sides in proportion</em>
<em />
<u><em>3rd photo:</em></u>
x = 4.5 or 4 1/2

<em>2x = 9</em>
<em>x = 4.5 or 4 1/2</em>
<em />
<u><em>4th photo:</em></u>
Length of string = 118.2 ft
<em>sin(40) = 76/x</em>
<em>x = 76/sin(40) = 118.2</em>
Answer:
Options (3), (4) and (5)
Step-by-step explanation:
1). a² - 9a + 7ab + 63b
= a(a - 9) + 7b(a + 9)
Now we can not solve this problem further.
Therefore, can't be factored by grouping.
2). 3a + 4ab - b - 12
= a(3 + 4b) - 1(b - 12)
We can't solve it further.
Therefore, can't be factored by grouping.
3). ab + 6b - 2a - 12
= b(a + 6) - 2(a + 6)
= (b - 2)(a + 6)
We can be factored this expression by grouping.
4). x³ + 9x²+ 7x + 63
= x²(x + 9) + 7(x + 9)
= (x² + 7)(x + 9)
Therefore, the given expression can be factored by grouping.
5). ay² + a - y² - 1
= a(y² + 1) - 1(y² + 1)
= (a - 1)(y² + 1)
This expression can be factored by the grouping method.
Options (3), (4) and (5) are the correct answers.
7x (2x^2 - 3) is your answer my dude/lady
2 feet and 1 in. Explanation is subtract 3’8 from 6’4 then add 9in too it. Feet can only go to 12in. But you’ll get 3’4. Then add 9 and you’ll get 3’13 so you’ll get 4’1 and then just subtract that from 6’4 and you get 2’1
The number of points Marco needs to bring his average up to 90% is 15points.
If there's a possible 25 possible points, and Marco has taken 5 quizzes;
Evidently, each quiz has weighs 5 points.
Mathematically;

- 2100 + 500x = 2250 + 450x
x = 3.
Therefore, he needs 5x points = 15 points to bring his average up to 90%.
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