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Solve using the quadratic formula x2 - 6x - 40=0 Question options: x = 10 or x = -4 x = 4 or x = -10 x = -7 or x = 7 x = -4 - √7 or x = -4 + √7 solve for x the find angle b

Answer :

Answer:

[tex]x=-10[/tex] or [tex]x=4[/tex]

Step-by-step explanation:

[tex]ax^2+bx+c=0[/tex]

[tex]x^2-6x-40=0[/tex]

[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

[tex]x=\frac{-6\pm\sqrt{6^2-4(1)(-40)}}{2(1)}[/tex]

[tex]x=\frac{-6\pm\sqrt{36+160}}{2}[/tex]

[tex]x=\frac{-6\pm\sqrt{196}}{2}[/tex]

[tex]x=\frac{-6\pm14}{2}[/tex]

[tex]x=-3\pm7[/tex]

[tex]x=-10[/tex] or [tex]x=4[/tex]
Always try to show the FOIL (first outer inner last) breakout if you can.

Think of the factors of 40 - fortunately only a few options come to mind.

10x4 and 8x5

Knowing the “inner” term is 6, this means the factors are 4 and 10 because 10-4=6

The inner term is negative, so the first term must have a -10 in it.


Therefore:

(x-10)*(x+4)=0

Or

X = 10

X = -4

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