tolong dijawab ya please sayano 23-26 jgn lupa pkai cara ya

26.
f(x) = 2x^2 - 3
f(a) = 2a^2 - 3 = 47
2a^2 = 47 + 3
2a^2 = 50
a^2 = 50/2
a^2 = 25
a = √25
a = 5