(adsbygoogle = window.adsbygoogle || []).push({}); How is charge/mass ratio derived in this example?!?!

Hello, I know there are many ways to derive an expression for "q/m", but I am having some troubles with this one. We are given:

(1/2)mv^2 = qV (mass, velocity, charge, voltage)

qvB = (mv^2) / r (charge, velocity, mag field, mass, velocity, radius of arc)

r = (mv) / (qB) (radius, mass, velocity, charge, mag field)

given these equations, we are supposed to come up with:

q/m = (2V) / (B^2 x r^2) (chargemass = 2Voltage / (mag field)^2 times (radius)^2)

Its probably a very simple step, I just don't see it. Any help is greatly appreciated, Thanks!

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# How is charge/mass ratio derived in this example?

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