I am NOT smarter than an fifth grader.?

Question

I'm trying to help me little brother with his math homework, and I can't figure it out!

if z^2 = 18 - 7z, what is Z?

that's z squared equals 18 minus seven times z, if the symbols are comfusing XP

thanks!

oh I feel so stupid, I knew how to do that.

thanks guys.

and no, he's not in 5th grade, he is in 6th though. it IS rediculous.

Answer 1

z^2 = 18 - 7z, what is Z

Solve for 0 first:

z^2 + 7z - 18 = 0
(z-2)(z+9) = 0
z = 2 or z = -9

Are they SERIOUSLY doing this stuff in FIFTH grade now? I'll never be able to help my daughter with homework anymore! yipes!

Answer 2

Well first you would set the whole equation equaled to zero
z^2+7z-18= 0
then you factor the equation (find out what multiplies to 18 and subtracts to 7.
(z+9)(z-2)
Then set each part equaled to zero and find z
z+9=0 z-2=0
So the answer could be either z= -9 or z=2
** their is absolutely no need for the quadratic formula

Answer 3

Put everything on one side of the equation:
z² +7z - 18 = 0.
Now factor the left-hand side:
(z+9)(z-2) = 0.
Set each factor to zero and solve:
z = -9 or z = 2.
Check the work:
81 -63 - 18 = 0
and
4+14-18 = 0.

Answer 4

it's a quadratic equation
z^2 +7z - 18 = 0

You can either use the quadratic forumla to solve or factor it directly. To factor it, you are looking for two numbers which multiple to -18 and sum to 7. These are 9 and -2. Thus you can rewrite as

(z - 2)(z + 9) = 0

so 2 and -9 are solutions

Answer 5

z is either -9 or 2. Move the terms to the same side to get z^2 + 7z - 18, then use the FOIL method to get (z + 9)(z - 2). The numbers that make this equal zero are -9 and 2, so they are solutions.

Answer 6

fake(there are various greater beneficial outdoors of the continental U.S.) 5 fake(sales haven't any color) pink-22 No"0's" incorrect The#2 won't have the capacity to do branch If the only is the #13 or the two are a million and a million that would rely on the 5th grader! pink is the only color interior the question. 2 fractions separated by employing a plus sign. That exchange into exciting, thank you.

Answer 7

z^2+7z-18=0
(z+9)(z-2)=0
z=-9 z=2
if this is 5th grade work, then your brother needs to go to a different school, this shouldnt be taught till at least 9th grade

Answer 8

z^2 =18 - 7z
z^2 -18 - 7z =0
z^2 +7z -18 = 0
z^2-2z +9z - 18
(z^2-2z)(9z -18)
z(z-2) +9(z-2)
(z-2)(z+9)=0
z-2=0 z+9=0
z=2 z= 9

Answer 9

z can be one of two numbers: -9 and 2. Since there is a squared term, one cannot put like terms together and solve. Treat it like a quadratic

Answer 10

z = 2, basically you are looking for value that would give you the same answer on both sides, seeing as z >3, you would always get a negavtive value...z<1 gives you too small of a value