Question

How do you solve using the completing the square method `5v^2-21=10v`?

Answer 1

`v=1+sqrt(26/5)orv=1-sqrt(26/5)`

Explanation:

`5v^2-21=10v=>5v^2-10v=21=>v^2-2v=21/color(red)5`
`:.v^2-2vcolor(red)(+1)=21/5color(red)(+1)=>(v-1)^2=26/5=(sqrt(26/5))^2`
`=>v-1=+-sqrt(26/5)=>v=1+-sqrt(26/5)`
`v=1+sqrt(26/5)orv=1-sqrt(26/5)`