Posted by lali on Thursday, April 7, 2011 at 9:10pm.
Please type your subject in the School Subject box. Any other words, including obscure abbreviations, are likely to delay responses from a teacher who knows that subject well.
sqroot(0)=0
you must find where is:
-13x+36=0
-13x=-36 Divide with -13
x=(-36)/(-13)
x=36/13
I have no idea what Anonymous did. That answer makes no sense.
x^2-13x+36 is the same as:
(x-4)(x-9)
Any number multiplied by 0 is 0. For example:
100 x 0 = 0
8 x 0 = 0
63655215777999400525 x 0 = 0
So if x-4 equals 0 OR x-9 equals zero, then we know that x-4 times x-9 equals zero.
x-4 = 0. In that case, x=4. (4-4 is zero)
x-9 = 0. So in that case, x=9. (9-9 = 0)
So x is either 4 or 9. Let's check to be sure.
4:
x squared is 16
13x is 52
36 is...well...36.
16 -52 + 36 does equal 0. So we are ok there.
9:
9 squared is 81
13 x 9 = 117
81 - 117 + 36 equals zero.
9 and 4 are your answers.
Side note: if writeteacher didn't correct your spelling of "math," I likely would not have seen this question. Be careful next time.