Hi there!
When we have an equation standard form...

...the formula of the discriminant is
D = b^2 - 4ac
When
D > 0 we have two real solutions
D = 0 we have one real solutions
D < 0 we don't have real solutions
1.) Find the value of the discriminant and the the number of real solutions of
x^2-8x+7=0
Plug in the values from the equation into the formula of the discriminant

D > 0 and therefore we have two real solutions.
2.) Find the value of the discriminant and the number of real solutions of
2x^2+4x+2=0
Again, plug in the values from the equation into the formula of the discriminant.

D = 0 and therefore we have one real solution.
~ Hope this helps you.
Median = 15.5
Please take a look at the image attached for an explanation.
Answer:
(c) Triangle Z Y X is similar to triangle C B A
Step-by-step explanation:
Triangles are similar when corresponding sides have the same ratio. Corresponding sides will have corresponding end point vertices. The similarity statement lists corresponding vertices in the same order.
__
<h3>corresponding sides</h3>
The side lengths, smallest to largest, for the two triangles are ...
- 3 cm -- ZY
- 6 cm -- YX
- 7 cm -- XZ
And for the other triangle, ...
- 6 cm -- BC
- 12 cm -- AB
- 14 cm -- AC
<h3>corresponding vertices</h3>
The points joining the each side to the next one longer, in order for the two triangles, are ...
Y, X, Z and B, A, C
The vertices corresponding to ZYX in the same order are CBA.
triangle ZYX is similar to triangle CBA