Answer:
[tex]x = \frac{70 + \sqrt{900} }{50}\\[/tex] or [tex]x = 2[/tex]
Or:
[tex]x = \frac{70 - \sqrt{900} }{50}\\[/tex] or [tex]x = \frac{4}{5}[/tex]
Step-by-step explanation:
Step 1 - Simplify by expanding the brackets:
[tex](5x - 7)^2\\(5x - 7)(5x - 7)\\25x^2 - 35x - 35x + 49\\25x^2 - 70x + 49 - 1\\25x^2 - 70x + 48 = 8[/tex]
Step 2 - Subtract 8 from both sides so the equation equals 0:
[tex]25x^2 - 70x + 48 - 8 = 8 - 8\\25x^2 - 70x + 40 = 0[/tex]
Step 3 - Use the quadratic formula:
[tex]x = \frac{-b +- \sqrt{b^2 - 4ac} }{2a}\\a = 25\\b = -70\\c = 40[/tex]
Plug variables in:
[tex]\frac{-(-70) +- \sqrt{(-70)^2 - (4 * 25 * 40)} }{2 * 25}[/tex]
[tex]\frac{70 +- \sqrt{4900 - 4000} }{50}\\\\\frac{70 +- \sqrt{900} }{50}\\[/tex]
So x is either:
[tex]x = \frac{70 + \sqrt{900} }{50}\\[/tex]
[tex]x = 2[/tex]
Or:
[tex]x = \frac{70 - \sqrt{900} }{50}\\[/tex]
[tex]x = \frac{4}{5}[/tex]
Hope this helps!
