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SOLUTION: Solve. x^2 – 7x – 4 = 0
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Question 88260
:
Solve. x^2 – 7x – 4 = 0
Answer by
jim_thompson5910(33401)
(
Show Source
):
You can
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Now let's use the quadratic formula to solve for x:
Starting with the general quadratic
the general form of the quadratic equation is:
So lets solve
(notice
,
, and
)
Plug in a=1, b=-7, and c=-4
Negate -7 to get 7
Square -7 to get 49
Multiply
to get
Combine like terms in the radicand (everything under the square root)
Simplify the square root
Multiply 2 and 1 to get 2
So now the expression breaks down into two parts
or
Which approximate to
or
So our solutions are:
or
Notice when we graph
we get:
when we use the root finder feature on a calculator, we find that
and
.So this verifies our answer