Question 636325
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
look it over ...
1) {{{3*(-3)^2 - 3*(-3) + 6 = 27 + 9 + 6 = 42}}}
2){{{sqrt((-7)^16) = 7^8}}}
3) 4b+3 |<span style="text-decoration: overline">(20b^3+7b^2+22b+27</span>
4) (2x^2-9xy+y^2) 
 + (-6x^2-6xy-y^2)
<u>    + (x^2+xy-4y^2)</u>
     -3x^2 - 14xy - 4y^2
5) {{{(m-7)/(m+7)}}}
6) 6x^2-5x+1=0  {{{sqrt(5^2 - 4*6 * 1) = sqrt(1)}}} = ±1,  2 real roots 
7) {{{t(t^2-3)/(t^2-9)}}}  Denominator CANNOT = 0, underfined for x = ± 3