CPhill

The interior angles of a quadrilateral sum to  360°

So.....

s + 2s + 3s + 2s  = 360              simplify

8s  = 360

s = 360  /  8  =    45°

a is a vertical  angle  to the 31°  angle....so it also  = 31°

And  since  a  and c opposite  interior angles between parallels.....they  are  equal

So

c = 31°

LOL!!!

Since  AB = AC, the  angles  ABC = ACB  = 72°

Bisecting  angle  ABC  means that  angle  ABD =  angle BAD  = 36°

Therefore....in triangle   ABD......AD = BD

And the  thitd  angle in this triangle, BDA  =  108°

So angle  BDC   =  180  - 108°  =  72°

And  angle  ACB =  DCB = 72°

So.....in triangle  BDC, angle  DCB = angle BDC    

So  BD = BC

So

BC =  BD  = AD

6x + 8y - 3z = -10     (1)

2x + 8y - 5z = 2        (2)

-5x - 8y + 4z = 7       (3)

Add ( 1)  and (3)   and we have

x + z =   -3       (4)

Add ( 2)  and (3)  and we have

-3x - z  =  9         (5)

Add ( 4)  and (5) and we  have  that

-2x  =  6

x =  6 /  -2  =  -3

And

x + z  = -3

-3 + z  =  -3

z  = 0

And

6(-3)  + 8y  - 3(0) = -10

-18   + 8y  = -10

8y  = 8

y  = 1

So  ( x,  y , z)  =   ( -3 , 1 , 0)  as CentsLord  found

The  roots  are   at  x = -6   x = -3   and  x  = 3

The  the possible polynomial   is   ( x + 6)  ( x + 3) ( x - 3)  =  (x + 6) ( x^2 - 9)

(8𝑥^6𝑦^4)(5𝑥^5𝑦^12) = 

8*5   * x^6 * x^5 * y^4 * y^12   =

40  x^11 y^16

Write

y  =   1/ ( x - 3) +  7             get  x  by itself

y  - 7   =  1/ ( x - 3) 

x - 3  =   1 / ( y - 7)

x =   1/ ( y - 7)  +  3              "swap" x and y

y  = 1/ ( x  - 7)   + 3    =  the inverse  and  x cannot  =  7

B and E  are congruent  to T

To add to what textot said....notice  that  the  graph "cuts"  the  x axis  at  x  = -4   but  it " kisses" the  x axis at  x = 7

A graph cutiing the x axis  will  always have an odd multiplicity root  at that point, but a graph "kissing" the x axis will have an even multiplicity root  at  that point

Thus......f(x) = (x + 4) ( x - 7)^2  is the only possibility