Answer:
(21 + 11)2 = 64
So, I don't think teachers do this, but this is my way of doing it
Okay, so first, I divided 64 by 2 :
64 ÷ 2 = 32
Then, I subtracted 11 from 32:
21
Now, to check, just do the problem :
(21 + 11)2 = 64
32 * 2 = 64
$124.56 because if you have 63% you change it to a decimal so it is not .63 and you multiply it by 146.16 and then add the 35 you get 124.56
1 Move all terms to one side.
{x}^{2}+15x+45=0
x
2
+15x+45=0
2 Use the Quadratic Formula.
x=\frac{-15+3\sqrt{5}}{2},\frac{-15-3\sqrt{5}}{2}
x=
2
−15+3
5
,
2
−15−3
5
3 Simplify solutions.
x=-\frac{3(5-\sqrt{5})}{2},-\frac{3(5+\sqrt{5})}{2}
x=−
2
3(5−
5
)
,−
2
3(5+
5
)