12 1/2 = 12.5
2.5mm = 2.5 cm
So the answer would be 15 cm
speed =distance traveled over time taveled... the ansewr will be in kilometres per hour
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:
$\boxed{ 2y-x=-4}$
2x²-19x-33=0
(2x-22 )(2x.+3 ) = 0
(x-11)(2x+3)=0
x-11=0 implies x = 11
2x+3=0 implies x = -3/2