Question

(15x-1)(1+15x)/3=2 2/3

Answer 1

15x+225x^2-1-15x/3=8/3

225x^2-1/3=8/3

225x^2-1-8/3=0

225x^2-9/3=0

9(25x^2-1)/3=0

3(25x^2-1)=0

25x^2-1=0

25x^2=1

x^2=1/25

x=1/5

Answer 2

$frac{225x^{2}-1}{3}=frac{8}{3}\ 225x^{2}-1=8\ 225x^{2}=9\ x^{2}=frac{9}{225}\ x=+-frac{3}{15}=+-frac{1}{5}$