Given the rectangle WXYZ, the angle m∠WXY=6a²-6
The given angle is a corner angle, and as you might remember all corner angles of a rectangle are right angles, so we can say that the given expression equals 90 degrees:
[tex]6a^2-6=90[/tex]
From this expression you can calculate the value of a.
First step is to add 6 to both sides of the equation so that the a-related term stays alone in the left side of the equation and all costants are in the other side:
[tex]\begin{gathered} 6a^2-6+6=90+6 \\ 6a^2=96 \end{gathered}[/tex]
Next divide both sides by 6:
[tex]\begin{gathered} \frac{6a^2}{6}=\frac{96}{6} \\ a^2=16 \end{gathered}[/tex]
And calculate the square to both sides of the variable to reach the possible value of a:
[tex]\begin{gathered} \sqrt[]{a^2}=\sqrt[]{16} \\ a=4 \end{gathered}[/tex]
Now, just because the result is positiv, that does not mean that is the only possible value for a, if you square -4 you can also get 16 as a result, so a can be negative 4 or positive 4:
a=±4
The correct option is B.
