Answer:
(1)
Multiplying by 3 both sides of the equality you get that

3u is in the Span of the vectors
.
(2)
That's not true, consider the following counter example.

is a linear combination of
but is NOT a linear combination of 
Step-by-step explanation:
(1)
As the hint indicates, you know that

Then, if you multiply both sides of the equality by 3, you get that

And that's it. 3u is in the Span of the vectors 
(2)
That's not true, consider the following counter example.

is a linear combination of
but is NOT a linear combination of 
Answer:
34
Explanation:
When 68 is decreased by 50%, that would mean that it is decreasing by half of that number. Half of that number would be 34 and that would be your answer.
Hello,
r²=(-4)²+(-6)²=16+36=52
x²+y²=52
A triangles angles always add up to 180 degrees, so if you were to subtract the 58 degrees from it that would leave you with 122. and with the 127 degrees all you would have to subtract the 127 from 180 to get 53 degrees which will also be the other given angle. So now you can subtract 53 from 122 leaving you with 69 degrees as your answer!