Answer:
Step-by-step explanation:
7x - 8(2x - 3) + 2 = 8
Expand bracket and Minus 2 on both sides
7x - 16x + 24 = 6
Minus 24 on both sides, and simplify the "x's"
-9x = -18
Divide by -9 on both sides
x = 2
Answer:
n = 19.89694
Step-by-step explanation:
You can work the problem using decimal numbers. There is no need to convert everything to integers. Trying to do so just gets you in trouble.
Subtract 2.2 from both sides:
-1.398 -2.200 = n/-5.53
-3.598 = n/-5.53
Now, multiply both sides by -5.53:
(-5.53)(-3.598) = n = 19.89694
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The one rule that cannot be violated in algebra is that <em>you must do the same thing to both sides of the equation</em>.
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Your "solution" so far has a couple of errors. The first is that you have apparently multiplied all of the numbers by 1000. Unfortunately, when you multiply a denominator by 1000, it is the same as dividing by 1000. So, you have multiplied the left side by 1000, multiplied one term on the right by 1000 and divided another term on the right by 1000. This turns the equation into something different than what you started with, and will give a wrong answer.
The second error is that you have subtracted 2200 only from the right side. This, too, will turn the equation into something different than what you started with, and will give a wrong answer.
Answer:
24x-2
Step-by-step explanation:
Perimeter is 2(L+w)
(10x-3)+(2x+2)
Combine like terms
12x-1
2(12x-1)
24x-2
Answer:
14
Step-by-step explanation:
Let's say Devaughn is x amount of years old and Sydney is y amount of years old.
Since the sum of their age is equal to 56, you would make the equation:
x+y=56
Now, set that aside and move on to the next step.
They are saying the Devaughn (x) is 3 times the number of years Sydney (y) is. So in mathematical terms you can create an equation stating:
3y=x because 3 times Sydney's age (y) would be Devaughn's age (x).
With the equations:
3y=x
x+y=56
You can plug in x in (x+y=56) as 3y because the other equation is saying that x is equal to 3y. So, that will give you 3y+y=56. Now, combine like terms or just simplify.
Simplifying 3y+y=56 would give you 4y=56, now just divide 56 by the 4 and you will get 14. This is saying that y=14. Now plug in y for the other equation (x+y=56):
x+14=56
Subtract 56 by 14 and it'll give you 42. That is saying x=42.
The question is asking for Sydney's age and i substituted her for the letter y which equaled 14.
Hope this helped :)
Here are two ways to solve
Method 1: Elimination
x+y = 3k ... start with the first equation
4x+4y = 12k ... multiply every term by 4
4x-6k = 2y ... move onto the second equation
4x-2y = 6k ... subtract 2y from both sides and add 6k to both sides
The system of equations turns into
4x+4y = 12k
4x-2y = 6k
which, when subtracted, leads to 0x+6y = 6k so y = k when you divide both sides by 6
Use y = k to find x
x+y = 3k
x+k = 3k
x = 2k
The answer is 2k
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Method 2: Substitution
x+y = 3k ... start with the first equation
y = -x+3k ... isolate y; subtract x from both sides
4x-6k = 2y ... move onto the second equation
4x-6k = 2(-x+3k) ... plug in y = -x+3k; solve for x
4x-6k = -2x+6k
4x+2x = 6k+6k
6x = 12k
x = 12k/6
x = 2k
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Whichever method you use, the answer is x = 2k