Answer:
[tex]\frac{1 + 4 \sqrt{5} }{7}[/tex]
Step-by-step explanation:
(7x-1)² = 80 Take the square roots of both sides
7x - 1 = √80 = √16 ×√5
7x - 1 = 4√5 Add +1 to both sides
7x = 1 + 4√5 Divide both sides by 7
[tex]x = \frac{1 + 4 \sqrt{5} }{7} [/tex]
