Since you need an isolated variable to use the substitution method, we need to re-arrange one of the equations. This will probably be easiest to do with the first one.
Add 5y to both sides of the first equation.
x=10+5y
Now, in the second equation, put in 10+5y in any spot that has an x.
2(10+5y)-10y=20
Distribute the 2 to both numbers in the parenthesis.
20+10y-10y=20
Combine like terms.
20=20
This means that the two equations are actually the same. You can see this if you multiply the whole first equation by 2
2(x-5y=10)
2x-10y=20, which is the same as the second equation. Therefore, the two equations are actually the same one.
The answer is x=16 because that’s how math works
Answer:
is the correct answer.
Step-by-step explanation:
We know that vertex equation of a parabola is given as:

where
is the vertex of the parabola and
are the coordinate of points on parabola.
As per the question statement:
The parabola opens upwards that means coefficient of
is positive.
Let 
Minimum of parabola is at x = 3.
The vertex is at the minimum point of a parabola that opens upwards.

Putting value of a and h in the equation:

Formula used: 
Comparing the equation formulated above with the options given we can observe that the equation formulated above is most similar to option A.
Comparing
and
13 = 9+k
k = 4
Please refer to the graph attached.
Hence, correct option is 
Answer:
-6
Step-by-step explanation:
-1+(-5)
You are moving down the numberline, then subtracting again because of the negative sign. -(1+5) is how I like to think of it.
So, 1+5=6, and you add the negative sign. -1+(-5)=-6.
Answer:
B. 1/6
Step-by-step explanation: