Answer:
x
Step-by-step explanation:
Answer:
option A and B

and

Step-by-step explanation:
we have

The formula to solve a quadratic equation of the form
is equal to

in this problem we have

so

substitute in the formula


so

and

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.