They are called vertical angles because the definition of vertical is: <span>in a direction, or having an alignment, such that the top is directly above the bottom. The "angles opposite each other when two lines cross" match the definition.</span>
Can you show me a picture of the problem?
The given equation is: 
To find the line perpendicular to it, we interchange coefficients and switch the signs of one coefficient.
The equation to a line perpendicular to it is:
$ 2y-x=c$
where, $c$ is some constant we have determine using the condition given.
It passes through $(2,-1)$
Put the point in our equation:
$2(-1)-(2)=c$
$c=-2-2$
$c=-4$
The final equation is:
$\boxed{ 2y-x=-4}$
Answer:
Step-by-step explanation:
First step plug the numbers into the equation.
-10/(5+2) = (-10/5) + (-10/2)
Solve both sides of the equation separately.
-10/(5+2) Use distributive property, multiply both 5 and 2 by -10.
= -50 + (-20) = -70
-10/5 + -10/2 Multiply the fractions so they can be added together.
-10/5*2 = -20/10 -10/2*5 = -50/10
-20/10 + -50/10 = -70
Now you have solved both equations and they are both equal to -70, so you have verified that the equations are equal to each other because they both equal -70.
