Answer:
x = -10
Step-by-step explanation:
9x-1=10x+9
9x-1+1=10x+9+1
9x=10x+10
9x-10x=10x-10x+10
-x=10
-x/-1=10/-1
x= -10
hope it's helpful ❤❤❤❤❤❤
THANK YOU.
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Answer:
1 and 1/4 liters of paint are needed for one door
Step-by-step explanation:
You can eliminate each answer choice out. For '4/5 liters' you know that if that amount was used, it wouldn't be reasonable since it would mean that the more was used for the other 3/5 door. 3 and 1.5 would be too much since it is over 2 liters. 2 liters wouldn't be logical since you paint 1 <em>and</em> 3/5 of a door and you only used 2 liters, no more or no less, basically what would you use for the other 3/5 door if this was the answer.
Hope this helps!
Answer:
a. 78.6 square feet
b. $7.86
Step-by-step explanation:
a. This simply asks us to calculate the area of the 10 feet diameter pool
Formula for area of circle is ;
pi * r^2 = pi * d^2/4
so Area = 22/7 * 10^2/4 = 78.60 square feet
b. This will be the area of the blanket multiplied by the price per square foot of the blanket
Mathematically, we have that as;
78.60 * 0.1 = $7.86
The correct answer is: [B]: " (2, 5) ".
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Given:
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-5x + y = -5 ;
-4x + 2y = 2 .
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Consider the first equation:
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-5x + y = -5 ; ↔ y + (-5x) = -5 ;
↔ y - 5x = -5 ; Add "5x" to each side of the equation; to isolate "y" on one side of the equation; and to solve in terms of "y".
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y - 5x + 5x = -5 + 5x
y = -5 + 5x ; ↔ y = 5x - 5 ;
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Now, take our second equation:
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-4x + 2y = 2 ; and plug in "(5x - 5)" for "y" ; and solve for "x" :
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-4x + 2(5x - 5) = 2 ;
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Note, 2(5x - 5) = 2(5x) - 2(5) = 10x - 10 ;
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So: -4x + 10x - 10 = 2 ;
On the left-hand side of the equation, combine the "like terms" ;
-4x +10x = 6x ; and rewrite:
6x - 10 = 2 ;
Now, add "10" to each side of the equation:
6x - 10 + 10 = 2 + 10 ;
to get:
6x = 12 ; Now, divide EACH side of the equation by "6" ; to isolate "x" on one side of the equation; and to solve for "x" ;
6x/6 = 12 / 6 ;
x = 2 ;
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Now, take our first given equation; and plug our solved value for "x" ; which is "2" ; and solve for "y" ;
_____________________________________
-5x + y = -5 ;
-5(2) + y = -5 ;
-10 + y = -5 ; ↔
y - 10 = -5 ;
Add "10" to each side of the equation; to isolate "y" on one side of the equation; and to solve for "y" ;
y - 10 + 10 = -5 + 10 ;
y = 5 .
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So, we have, x = 2 ; and y = 5 .
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Now, let us check our work by plugging in "2" for "x" and "5" for "y" in BOTH the original first and second equations:
______________________________
first equation:
-5x + y = -5 ;
-5(2) + 5 =? -5?
-10 + 5 =? -5 ? YES!
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second equation:
-4x + 2y = 2 ;
-4(2) + 2(5) =? 2 ?
-8 + 10 =? 2 ? Yes!
_______________________________________________________
So, the answer is:
___________________________________________________________
x = 2 , y = 5 ; or, "(2, 5)" ; which is: "Answer choice: [B] " .
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<span>E[Y] = 0.4·1 + 0.3·2 + 0.2·3 + 0.1·4 = 2
E[1/Y] =0.4·1/1 + 0.3·1/2 + 0.2·1/3 + 0.1·1/4 = 0.4 + 0.15 + 0.0666 + 0.025?0.64
V[Y] =E[Y2]-E[Y]2= (0.4)·12+(0.3)·22+(0.2)·32+(0.1)·42-22= 0.4+1.2+1.8+1.6-4= 5-4 = 1</span>
