SOLUTION: Find a negative real number such that the square of the sum of the number and 21 is equal to 144 (If there are two correct answers, either answer can be entered.)

Algebra.Com
Question 1135200: Find a negative real number such that the square of the sum of the number and 21 is equal to 144
(If there are two correct answers, either answer can be entered.)
Found 2 solutions by josmiceli, ikleyn:
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
Let = the negative real number



complete the square

( what I started with )



and also:



-----------------------------
check the answers:



OK



OK
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.

            I just solved this problem at this forum couple of days ago under this link

https://www.algebra.com/algebra/homework/word/finance/Money_Word_Problems.faq.question.1135082.html

https://www.algebra.com/algebra/homework/word/finance/Money_Word_Problems.faq.question.1135082.html


            > > > in much simpler way. < < <


For your convenience, I copy and paste here that my solution AGAIN

-------------- 

 = 144  ===============> which implies two consequences to be considered:


a)  x+21 =  = 12  ====>  x = 12 - 21 = -9.


b)  x+21 =  = -12  ====>  x = -12 - 21 = -33.


ANSWER.  The problem has TWO SOLUTIONS. They are the numbers -9 and -33.

Answered and solved.


RELATED QUESTIONS

Find a negative real number such that the square of the sum of the number and 21 is... (answered by josgarithmetic,ikleyn)
Find a negative real number such that the square of the sum of the number and 17 is... (answered by josgarithmetic)
find a negative real number such that the square of the sum of the number and 6 is equal (answered by JulietG)
Find a negative real number such that the square of the sum of the number and 3 is equal... (answered by Alan3354,addingup)
Find a negative real number such that the square of the sum of the number and 15 is equal (answered by josgarithmetic)
there exist two real number x, y such that the product of their sum and difference is... (answered by ikleyn)
there exist two real number x, y such that the product of their sum and difference is... (answered by ikleyn)
The square of a number is equal to the sum of 21 and 4 times the number. Find the... (answered by Fombitz)
The difference of the square of a number and 21 is equal to 4 times that number. Find the (answered by Alan3354)