First, add color(red)(10)10 to each side of the equation to isolate the radical while keeping the equation balanced:
sqrt((5y)/6) - 10 + color(red)(10) = 4 + color(red)(10)√5y6−10+10=4+10
sqrt((5y)/6) - 0 = 14√5y6−0=14
sqrt((5y)/6) = 14√5y6=14
Next, square each side of the equation to eliminate the radical while keeping the equation balanced:
(sqrt((5y)/6))^2 = 14^2(√5y6)2=142
(5y)/6 = 1965y6=196
Now, multiply each side of the equation by color(red)(6)/color(blue)(5)65 to solve for yy while keeping the equation balanced:
color(red)(6)/color(blue)(5) xx (5y)/6 = color(red)(6)/color(blue)(5) xx 19665×5y6=65×196
cancel(color(red)(6))/cancel(color(blue)(5)) xx (color(blue)(cancel(color(black)(5)))y)/color(red)(cancel(color(black)(6))) = 1176/5
y = 1176/5
To check the solution we need to substitute color(red)(1176/5) for color(red)(y), calculate each side of the equation and ensure the two results are equal:
sqrt((5color(red)(y))/6) - 10 = 4 becomes:
sqrt((5 xx color(red)(1176/5))/6) - 10 = 4
sqrt((color(red)(cancel(color(black)(5))) xx color(red)(1176/color(black)(cancel(color(red)(5)))))/6) - 10 = 4
sqrt(1176/6) - 10 = 4
+-sqrt(196) - 10 = 4
+-14 - 10 = 4
4 = 4 or -24 = 4
The -14 result of the square root is extraneous.
Therefore, 4 = 4 and the solution is shown to be correct.