What makes this a perfect square K^2 - 30k +?

225

Step-by-step explanation:

in (a+b)^2, it becomes a^2+2ab+b^2.  A in this case would be "K" and b in this case would be 15.  K^2+2(K)(15)+(15)^2.  That equals k^2+30k+225.  The last part is 225.  

My trick to do this quickly is you get the "2ab" part.  You divide the coefficient by 2 and then square it.  For example, the coefficient in 30K is 30.  30/2 is 15.  15^is 225.

step-by-step explanation:

i think something is missing in your question because y-1=(x-12) would not pass through the point (-4,-3). because if you replace x by -4 your are supposed to find y=-3 which is not the case her. if you replace x by -4 you find =-15.

i assume the right equation is y-1=1/4*(x-12) because this one is passing through both your points (if you are interested to know how i found that out i can tell you).

in this equation if i replace x by -4 i find y=-3 and if i replace x by 12, i find y=1 so the line representing this equation is passing through those 2 points.

then the standard form of the equation is finding an expression of y in function of x

y-1=1/4*(x-12)

y=x/4-3+1

y=x/4-2

hope that .

do you confirm there was a mistake in the question?