How do you solve #n^2-5=-4#?

2 Answers
Sep 1, 2016

#n=+-1#

Explanation:

To solve a quadratic equation we require to equate it to zero.

The first step is therefore to add 4 to both sides of the equation.

#rArrn^2-5+4=cancel(-4)+cancel(4)=0#

#rArrn^2-1=0" is the equation to be solved"#

Now #n^2-1 # is a #color(blue)"difference of squares"#

#rArr(n-1)(n+1)=0#

solve: #n-1=0rArrn=1#

solve #n+1=0rArrn=-1#

Thus the solutions to the equation are #n=+-1#

Sep 4, 2016

#n = +-1#

Explanation:

Although this is a quadratic equation, it is a special case because there is no 'n' term.

Isolate the #n^2 # term.

#n^2 = -4+5 #

#n^2 = 1#

#n = +-1#