Question

A = {x : x ∈ R, 2x + 11 = 15}

d. B = {x : x^2 = x, x ∈ R} write in roster form ​

Answer 1

$\mathbb{\red{\huge{HEY\:MATE}}}$

$\boxed{HERE\:IS\:YOUR\:ANSWER}$

$\mathfrak{\green{ANSWER:}}$

2x + 11 = 15

2x = 15 - 11

2x = 4

x = 4/2

x = 2

Then,

A = {2}.