Answer:well i do know what exaclty what you were reading so i have no clue add a coment about it ill read then answer :)
Step-by-step explanation:
With exponents of 10, the exponent really just tells you how many zeroes there are behind the 1. So, for example, 10^4=10000 (4 zeroes behind 1). When multiplying decimals by exponents of 10, you move the decimal to the right, and the amount of places is the exponent number. For example, if I multiply 5.34 by 10^2, I move the decimal over to the right 2 times and get 534.
So, if you just multiply these you get 9.36*10000, which is 93600.
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" ;
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-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:
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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!
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So, the answer is:
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x = 2 , y = 5 ; or, "(2, 5)" ; which is: "Answer choice: [B] " .
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To solve equations, you isolate the variable you are solving for on one side and everything else on the other side.
The first step to solving this equation is to combine like terms.
Combining like terms means to add up all terms that have the same variable(s) and exponent.
If no exponent is shown, then a 1 exponent is implied. The reason why we don't show a term raised to the first power is that it doesn't have any effect on the term.
I see three terms with the x variables. We can combine them. Why? Because they all have the same variable and exponent.
I'll rearrange the left-hand side to combine all the terms with the x variable.
Now we have -3 + 2x - 4x - 2x = -6
Combine all terms that have the x variable.
-3 + 2x - 4x - 2x = -6
-3 - 4x = -6
Now we have -3 - 4x = -6
What can we do now to isolate the x variable on the left-hand side?
For starters, we can add 3 to each side of the equation.
That way the -3 term will disappear.
-3 - 4x + 3 = -6 + 3
-4x = -3
Last step.
The x variable is being multiplied by the -4. If we reverse that operation
we can get the value of x.
-4x / -4 = 3 / -4
x = 3/-4 or x = -0.75
Answer:
x=28
Step-by-step explanation:
We can use similar triangles and proportions to solve this problem. Put the side of the small triangle over the same side of the larger triangle.
x 42
---------- = ----------
x+10 42+15
Simplify
x 42
---------- = ----------
x+10 57
Using cross products
57x = 42 (x+10)
Distribute
57x = 42x+420
Subtract 42x from each side
57x-42x = 42x-42x +420
15x = 420
Divide each side by 15
15x/15 = 420/15
x=28
