Answer:
The number is -1/2
Step-by-step explanation:
Let x be the number
2x+8 = 7
Subtract 8 from each side
2x+8-8 = 7-8
2x = -1
Divide each side by 2
2x/2 =-1/2
x = -1/2
The number is -1/2
Answer:
482
Step-by-step explanation:
We can see that the numbers shown resemble an arithmetic sequence because they have a common difference. The formula for the nth term of an arithmetic sequence is:
Where 
is the first term, 
is the nth term, and 
is the common difference. To find the 61st term, all we need is the first term and the common difference. By looking at what given, we can say the first term is 2. Now, to find the common difference, we find the difference of a term from the term before it. In this case we can do 
, which is 
, or the common difference. Since we have everything we need, it can be plugged into the equation:
So, the 61st term is 482.
-6n-20=-2n+4-12n
-6n-20=-14n+4
+6n +6n
-20=-8n+4
-4 -4
-24=-8n
/8 /8
n=-3
-
Answer:
Linda: 3 ; Laura: 15
Step-by-step explanation:
Note that Linda + Laura's age is 18, and that Linda is 12 years younger than her sister.
Let "Linda" = x , "Laura" = y:
x + y = 18
x = y - 12
First, plug in y - 12 for x in the first equation:
(y - 12) + y = 18
Simplify.
2y - 12 = 18
Isolate the variable (y). Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS. First add, then divide.
2y - 12 (+12) = 18 (+12)
2y = 18 + 12
2y = 30
(2y)/2 = (30)/2
y = 30/2
y = 15
Next, plug in 15 for y in the second equation (the other equation would work too).
x = y - 12
x = (15) - 12
x = 3
Linda's age is 3, Laura's age is 15.
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