SOLUTION: Using {{{ (a-b)^2 = (a+b)^2-4ab }}} Find the Value of {{{ ((a-b)^2) }}} if {{{ a }}} and {{{ b }}} are the roots for {{{ y = x^2 + 5x - 7}}}

Algebra ->  Equations -> SOLUTION: Using {{{ (a-b)^2 = (a+b)^2-4ab }}} Find the Value of {{{ ((a-b)^2) }}} if {{{ a }}} and {{{ b }}} are the roots for {{{ y = x^2 + 5x - 7}}}      Log On


   

Question 978045: Using +%28a-b%29%5E2+=+%28a%2Bb%29%5E2-4ab+
Find the Value of +%28%28a-b%29%5E2%29+ if +a+ and +b+ are the roots for +y+=+x%5E2+%2B+5x+-+7
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The roots for +y=x%5E2%2B5x-7 are
x=%28-5-sqrt%2853%29%29%2F2 and x=%28-5%2Bsqrt%2853%29%29%2F2.


The rest of the solution to the question is several arithmetic steps.



%28-5%29%5E2-%28-5-sqrt%2853%29%29%28-5%2Bsqrt%2853%29%29, and recognize the formula for difference of squares.

25-%28%28-5%29%5E2-%2853%29%29

25-25%2B53

highlight%2853%29