What is the simplified form of -3z^2(z+2)- 4(z^2+1)?
A. -7x^2 + 1
B. -3z^3 -4z^2 - 6z -4
C. -3z^3 - 2z^2 - 4
D. -3z^3 -10z^2 -4

x=-2

step-by-step explanation:

i began by flipping the problem to give me x= on the left (keeps it clearer for me).   so my problem simply became 10x-3=4x-6.  

1)   subtract 4x from the right side, which equals 0.   you do the same to the left of the equal as the right; therefore, subtract 4x from 10x, leaving 6x on the left.

              10x-3=4x-6   :   4x-4x on the right leaves only the -6        

2)             6x-3= 0-6 :    

                6x+3=   -6

3) divide

sorry for any inconvenience this may have caused try again

try again.

hello,

elba writes the following proof for the theorem: if the diagonals of a quadrilateral bisect each other, the quadrilateral is a parallelogram:

elba's proof

1. for triangles aob and cod, angle 1 is equal to angle 2 as they are vertical angles.

2. ao = oc and bo = od because it is given that diagonals bisect each other.

3. therefore, the triangles aob and cod are congruent by sas postulate.

4. similarly, triangles aod and cob are congruent.

5. by cpctc, angle abd is equal to angle cdb and angle adb is equal to angle cbd.

6. as the are congruent, the opposite sides of quadrilateral abcd are parallel.

7. therefore, abcd is a parallelogram.

which is the missing phrase in elba's proof?

answer - opposite