Answer:
30
Step-by-step explanation:
For a = <xa, ya> and b = <xb, yb>, the dot product is the sum of products ...
a·b = (xa)(xb) + (ya)(yb)
Substituting the given information, you have ...
a·b = 5·4 + 2·5 = 20 + 10
a·b = 30
_____
Some graphing calculators can do such math. There are also dot product calculators available on the Internet. If you have quite a few of these to calculate, you can put the appropriate formula into a spreadsheet.
563+8=571 burgers to start with
Easy,
the Pythagorean theorem is:

The a and b, being a value that you HAVE
and
c, being the value you are trying to find.
Example: have 1,2 for a triangle what is the third side?

1+4=

5=

Then, just square root to find c.

=c
2.2≈c
Width is x - 3
A
=
x
2
+
6
x
−
27
=
(
x
+
9
)
(
x
−
3
)