Answer:
(4 + u)(16 – 4u + u2)
Step-by-step explanation:
64 + u3.
= 43 + u3.
= (4 + u)(42 – 4.u + u2).
= (4 + u)(16 – 4u + u2).
Answer:
35
Step-by-step explanation:
If triangles AMN and ABC are similar, then
AM/AB = AN/AC
or
AM/(AM + MB) = AN/(AN + NC)
Check if this is true:
AM/AB = 21/(21 + 9) = 21/30 = 7/10
AN/AC = 14/(14 + 6) = 14/20 = 7/10
The angle at vertex A is common to both of the triangles.
Then by the side-angle-side (SAS) similarity theorem, the triangles are indeed similar.
Answer:

Step-by-step explanation:
The sum you are trying to understand is this.

Remember that in general when you have a geometric series
you have that
and that equality is true as long as
.
Therefore here we have
and 
Therefore we can use the formula and

Step-by-step explanation:
Lines that are tangent to a circle are perpendicular to the radius of the circle.
Lines that are tangent to a circle are congruent