4y^2-25y+21=0

Solution for 4y^2-25y+21=0 equation:

Simplifying
4y2 + -25y + 21 = 0

Reorder the terms:
21 + -25y + 4y2 = 0

Solving
21 + -25y + 4y2 = 0

Solving for variable 'y'.

Factor a trinomial.
(1 + -1y)(21 + -4y) = 0

Subproblem 1
Set the factor '(1 + -1y)' equal to zero and attempt to solve:

Simplifying
1 + -1y = 0

Solving
1 + -1y = 0

Move all terms containing y to the left, all other terms to the right.

Add '-1' to each side of the equation.
1 + -1 + -1y = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -1y = 0 + -1
-1y = 0 + -1

Combine like terms: 0 + -1 = -1
-1y = -1

Divide each side by '-1'.
y = 1

Simplifying
y = 1
Subproblem 2
Set the factor '(21 + -4y)' equal to zero and attempt to solve:

Simplifying
21 + -4y = 0

Solving
21 + -4y = 0

Move all terms containing y to the left, all other terms to the right.

Add '-21' to each side of the equation.
21 + -21 + -4y = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -4y = 0 + -21
-4y = 0 + -21

Combine like terms: 0 + -21 = -21
-4y = -21

Divide each side by '-4'.
y = 5.25

Simplifying
y = 5.25
Solution
y = {1, 5.25}