To find the mean you add all the numbers and divide it by the amount of numbers there is so add
6+9+15+22+30+36=118
there is 6 number so divide 118 by 6
118/6=<span>19.6666666667 rounded to the nearest tenth it would be 20
So your mean would be 20
let me know if you have any questions</span>
It is given that
a+b=20 -------------------- (1)
b+c=30 -----------------------(2)
We have to calculate
3 a + 4 b +7 c
Now multiplying equation(1 )by 3,we get
3 a+ 3 b=60 ----------------------------------(3)
and Multiplying equation( 2) by 4,we get
4 b + 4 c=120 -----------------------------------(4)
Adding expression (3) and (4),we get i.e left hand side of 3 to left hand side of 4 and right hand side of 3 to right hand side of 4.
3 a+ 3 b+ 4 b+ 4 c=60+120
Adding like terms, we get
3 a+ 7 b+ 4 c =180, Which is the required solution.
Answer:
2√3
Step-by-step explanation:
You recognize this as a 30°-60°-90° triangle, so you know the hypotenuse (R) is twice the length of the shortest side (√3).
The magnitude of R is 2√3.
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In case you haven't memorized the ratios for a 30°-60°-90° triangle, you can use trigonometry and the fact that ...
Sin = Opposite/Hypotenuse
sin(30°) = √3/R
R = √3/sin(30°) = √3/(1/2) = 2√3
Of course, doing this on your calculator will give a numerical answer, which you may not want.
So
Total cost of the workbooks is d
And the number of workbooks is t
Therefore d = 95
95=19t
t=95/19=5
5 workbooks
1)
x^2 + 4 = 0 Subtract 4 from each side
x^2 = -4
You cannot square a number to get a negative number. No real solution. (If you have learned about imaginary numbers, answer is 2i)
2)
<span>x^2+x-6=0 Factor. 3 and -2 add up to 1, and multiply to -6
(x+3)(x-2) = 0
Zero Product Property: Which numbers would put a zero in one of the parentheses?
x = -3 or x=2
3) </span><span>x^2-6x+7=0
Completing the Square:
Take half of b (-6), square it, and add/subtract that coefficient
x^2 - 6x + 9 - 9 + 7 = 0
(x -3)^2 - 2 = 0 Add 2 to both sides
(x-3)^2</span> = 2 Take the square root of both sides
<span>(x-3) = </span>√2 or -√2 Add 3 to both sides
<span>x = 3 + </span>√2 or 3 - √2<span>
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