Plywood1: x = width ; length = 2x
1) x (2x) = 4.5
2) 2x² - 4.5 = 0
a = 2 ; b = 0 ; c = -4.5
3) [tex]x = \frac{-b \pm\sqrt{b^2-4ac} }{2a} = \frac{0 \pm\sqrt{0-4(2)(-4.5)} }{2(2)}= \frac{\pm6}{4} = \boxed{\frac{3}{2}}[/tex]
Plywood2: x = width ; length = 2x-1.4
1) x (2x-1.4) = 16
2) 2x² -1.4x -16 = 0
a = 2 ; b = -1.4 ; c = -16
3) [tex]x = \frac{-b \pm\sqrt{b^2-4ac} }{2a}=\frac{1.4 \pm\sqrt{1.96-4(2)(-16)} }
{2(2)}=\frac{1.4 \pm11.4 }{4}=\boxed{3.2}[/tex]
Plywood3: x = width ; length = 5-x
1) x (5-x) = 6
2) -x² +5x -6 = 0
a = -1 ; b = 5 ; c = -6
3) [tex]x = \frac{-b \pm\sqrt{b^2-4ac} }{2a}=\frac{-5 \pm\sqrt{25-4(-1)(-6)} }{2(-1)}=\frac{-5 \pm1}{-2}[/tex]
[tex]\boxed{x_1=3}[/tex]
[tex]\boxed{x_2=2}[/tex]
