Difference between revisions of "1963 TMTA High School Algebra I Contest Problem 28"
Coolmath34 (talk | contribs) (Created page with "== Problem == If we add its square to a certain number, the sum is <math>72.</math> Find the number. <math>\text{(A)} \quad 9 \quad \text{(B)} \quad 6 \quad \text{(C)} \quad...") |
|||
| Line 5: | Line 5: | ||
== Solution == | == Solution == | ||
| − | Let the number be <math>x.</math> Then we have <math>x^2 + x = 72.</math> Solving yields <math>x = -9</math> and <math>x=8 | + | Let the number be <math>x.</math> Then we have <math>x^2 + x = 72.</math> Solving yields <math>x = -9</math> and <math>x=8.</math> |
| + | |||
| + | We see that <math>x=-9</math> is an option, so the answer is <math>\boxed{\text{(D) -9}.}</math> | ||
| + | |||
| + | (The previous answer was <math>\boxed{\text{(E) NOTA}}</math>, but that is not necessarily true because <math>x=-9</math> is still a possible value for that "certain number".) | ||
| + | |||
== See Also == | == See Also == | ||
{{Succession box | {{Succession box | ||
Revision as of 14:42, 26 March 2023
Problem
If we add its square to a certain number, the sum is 
Find the number.
Solution
Let the number be 
Then we have 
Solving yields 
and 
We see that 
is an option, so the answer is 
(The previous answer was 
, but that is not necessarily true because is still a possible value for that "certain number".)
See Also
| 1963 TMTA High School Mathematics Contests (Problems) | ||
| Preceded by Problem 27 |
TMTA High School Mathematics Contest Past Problems/Solutions | Followed by Problem 29 |
