SOLUTION: The square of a number increased by 3 times the number is 28. Find the positive number. *I think I'm supposed to start with x^2(x squared)+3(x+1)=28, and then turn it into x^2(

Algebra.Com
Question 1159985: The square of a number increased by 3 times the number is 28. Find the positive number.
*I think I'm supposed to start with x^2(x squared)+3(x+1)=28, and then turn it into x^2(x squared)+3x+3=28, but I'm not sure of how to continue(or if this is right), so any help is appreciated.
Thanks!
Found 3 solutions by MowMow, ikleyn, MathTherapy:
Answer by MowMow(42)   (Show Source): You can put this solution on YOUR website!
x = 'the number'
x^2 is the square of the number
+3x is three times the number
So x^2 + 3x = 28
x^2 + 3x - 28 = 0
Factored:
(x-4)(x+7) = 0
x-4 = 0
x = 4
and (x+7) = 0
x + 7 = 0
x = -7
The number could be either 4 or -7
Answer by ikleyn(52788)   (Show Source): You can put this solution on YOUR website!
.

Since the problem asks for positive number ONLY,

the correct answer is x= 4.



Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

The square of a number increased by 3 times the number is 28. Find the positive number.
*I think I'm supposed to start with x^2(x squared)+3(x+1)=28, and then turn it into x^2(x squared)+3x+3=28, but I'm not sure of how to continue(or if this is right), so any help is appreciated.
Thanks!
NO, you're WRONG!

Where did you get 3(x + 1) from? It says "3 times the number." Isn't that 3x, with x being the number?

Therefore, shouldn't the equation be: x2 + 3x = 28, which then results in: x2 + 3x - 28 = 0?

Solve that for x and you'll get 2 values for x. Then, give your answer based on this request: "Find the positive number."  

RELATED QUESTIONS


the square of a positive number is equal to 8 times the number increased by 20. find the... (answered by mananth)

the square of a positive number increased by 4 times the number is equal to 140 find the... (answered by macston)

The square of a positive number increased by 4 times the number is equal to 140. Find the  (answered by fractalier,MathLover1)

find a positive real number such that its square is equal to 3 times the number,... (answered by ewatrrr)

the square of a positive number increased by twice the number equals 3. Find the... (answered by ankor@dixie-net.com)

M^2-8m-37=-4
I'm not even sure how to start I think I am supposed to complete the square  (answered by mananth)

If the square of a positive number is increased by 3 times the number,the result is... (answered by ReadingBoosters,stanbon)

If 5 times the value of a number is increased by 3 the result is 28 what is the number? I  (answered by stanbon)

The square of a number added to 3 times the number is 28. Find the... (answered by Fombitz)