Question 223459
Solve for y:
{{{5y^4-7 = 73}}} Add 7 to both sides.
{{{5y^4 = 80}}} Divide both sides by 5.
{{{y^4 = 16}}} Take the fourth root of 16. {{{16 = 2^4}}}
{{{highlight(y = 2)}}} or {{{highlight(y = -2)}}}
You really get four solutions to this quartic equation, two pairs of double roots.
2, 2, -2, and -2