this is written as
[tex]2n + 7 \geqslant 27[/tex]
change the greater than or equal to sign to equal to in order to solve it
thus
[tex]2n + 7 = 27[/tex]
[tex]2n = 27 - 7[/tex]
[tex]2n = 20[/tex]
dividing through by 2
[tex] \frac{2n}{2} = \frac{20}{2} [/tex]
[tex]n = 10[/tex]
{[tex]{n:n \geqslant 10}[/tex]}