Algebra homework to do and I need help
A number decreased by 5 and then doubled is equal to the same number increased by 25. What is the number?
First you identify your variable, for our sake lets use x:
x= number in question
Next you write the equation given in the question:
Next you use the distributive property and multiply 2 by both x and negative 5 to get:
Now you want to get all of the x's to one side so you subtract the x on the right, fro the one on the left giving you:
Then you simply add 10 to 25 giving you the answer of x=35.
n = unknown number
Decreased by 5 then doubled means (n - 5)*2
The same number increased by 25 means n + 25
(n - 5)*2 = n + 25 Equation found from the story problem
2n - 10 = n + 25 Distribute the 2
2n = n + 35 Add 10 to each side
n = 35 Subtract n from each side