How do you solve -7n^2=-448?

2 Answers
Jim G.
Sep 1, 2016

n=+-8

Explanation:

Divide both sides by -7 so as to isolate the n^2 term.

(cancel(-7)^1 n^2)/cancel(-7)^1=(cancel(-448)^(64))/cancel(-7)^1rArrn^2=64

now take the square root of both sides

sqrt(n^2)=+-sqrt64rArrn=+-8

EZ as pi
Sep 1, 2016

n= 8 or n = -8

Explanation:

This is a quadratic equation, it can be solved by factorising.

-7n^2 = -448 larr div" "-7 to simplify. Divide on both sides.

n^2 = 64 larr make it =0

n^2 -64 larr difference of two squares.

(n+8)(n-8) = 0

Either factor can be equal to 0.

If n+8 = 0 rarr n = -8

If n-8 = 0 rarr n = 8

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