Question 977541
How can I solve for the value(s) of the variable of 2s^2-98=0?
<pre>
Either of two ways:

First way:

{{{2s^2-98}}}{{{""=""}}}{{{"0"}}}

Divide both sides by 2:

{{{s^2-49}}}{{{""=""}}}{{{"0"}}}

Factor the left side as the difference of squares:

{{{(s-7)(s+7)}}}{{{""=""}}}{{{"0"}}}

Use the zero-factor principle:

{{{s-7}}}{{{""=""}}}{{{"0"}}}; {{{s+7}}}{{{""=""}}}{{{"0"}}}
  {{{s}}}{{{""=""}}}{{{7}}};    {{{s}}}{{{""=""}}}{{{-7}}};

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Second way:

{{{2s^2-98}}}{{{""=""}}}{{{"0"}}}

Add +98 to both sides:

{{{2s^2}}}{{{""=""}}}{{{98}}}

Divide both sides by 2:

{{{s^2}}}{{{""=""}}}{{{49}}}

Use the principle of square roots:

{{{s}}}{{{""=""}}}{{{"" +- sqrt(49)}}}

{{{s}}}{{{""=""}}}{{{"" +- 7}}}

Either way, the values of the variable s are 7 and -7.


Edwin</pre>