What is y^2+10y-4=?

it needs a number to be equal to if you want it to be solved for the value of y

You must have input it wrong, the calculator comes up with no solution.

Solve for y:
y^2 + 10 y - 4 = 0

Add 4 to both sides:
y^2 + 10 y = 4

Add 25 to both sides:
y^2 + 10 y + 25 = 29

Write the left hand side as a square:
(y + 5)^2 = 29

Take the square root of both sides:
y + 5 = sqrt(29) or y + 5 = -sqrt(29)

Subtract 5 from both sides:
y = sqrt(29) - 5 or y + 5 = -sqrt(29)

Subtract 5 from both sides:
y = sqrt(29) - 5                    or                    y = -5 - sqrt(29)