How do you solve $-2k^2=-162$ ?

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Answer 1 · 2016-08-18T11:33:23

$k = -2, or k= +2$

In solving a quadratic equation we usually make it = 0. However, in this case there is no term $x$ , so we can use it in this form.

Isolate the variable.

$-2k^2 = -162 " "div -2$

$k^2 = 81" find square root"$

$k = +-sqrt81$

$k = 9 or k = -9$

Another method....

$-2k^2 +162 =0 " "div -2$

$k^2 - 81= 0" factorise"$

$(k+2)(k-2) = 0$
Each factor can be 0.

$k = -2, or k= +2$

How do you solve -2k^2=-162-2k^2=-162?