Answer:
x = √10,-√10
explanation:
5x2 + 1 = 51
you would carry the +1 to the other side making it
5x2=51-1
which is 5x2=50
this equation above can then be turned into
x2=50÷5
which goes on to form the equation
x2=10
this can then be turned into x=the square root of ten
and since it is know that when an equation is x2 whether it is negative or positive it would result in the same answer
but yeah I'm not smart or whatever but I hope this helps
not too sure it's correct though