Answer:
y = 3
Step-by-step explanation:

Answer: Rewrite equations:
5x+y=−13;6x+6y=−6
Step: Solve5x+y=−13for y:
5x+y=−13
5x+y+−5x=−13+−5x(Add -5x to both sides)
y=−5x−13
Step: Substitute−5x−13foryin6x+6y=−6:
6x+6y=−6
6x+6(−5x−13)=−6
−24x−78=−6(Simplify both sides of the equation)
−24x−78+78=−6+78(Add 78 to both sides)
−24x=72
−24x
−24
=
72
−24
(Divide both sides by -24)
x=−3
Step: Substitute−3forxiny=−5x−13:
y=−5x−13
y=(−5)(−3)−13
y=2(Simplify both sides of the equation)
Answer:
x=−3 and y=2
Step-by-step explanation:
Answer:
25.5
Step-by-step explanation:
Answer:


Step-by-step explanation:
Let
. We have that
if and only if we can find scalars
such that
. This can be translated to the following equations:
1. 
2.
3. 
Which is a system of 3 equations a 2 variables. We can take two of this equations, find the solutions for
and check if the third equationd is fulfilled.
Case (2,6,6)
Using equations 1 and 2 we get


whose unique solutions are
, but note that for this values, the third equation doesn't hold (3+2 = 5
6). So this vector is not in the generated space of u and v.
Case (-9,-2,5)
Using equations 1 and 2 we get


whose unique solutions are
. Note that in this case, the third equation holds, since 3(3)+2(-2)=5. So this vector is in the generated space of u and v.