-16t^2+40t+70=0

Solution for -16t^2+40t+70=0 equation:

Simplifying
-16t2 + 40t + 70 = 0

Reorder the terms:
70 + 40t + -16t2 = 0

Solving
70 + 40t + -16t2 = 0

Solving for variable 't'.

Factor out the Greatest Common Factor (GCF), '2'.
2(35 + 20t + -8t2) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(35 + 20t + -8t2)' equal to zero and attempt to solve:

Simplifying
35 + 20t + -8t2 = 0

Solving
35 + 20t + -8t2 = 0

Begin completing the square.  Divide all terms by
-8 the coefficient of the squared term: 

Divide each side by '-8'.
-4.375 + -2.5t + t2 = 0

Move the constant term to the right:

Add '4.375' to each side of the equation.
-4.375 + -2.5t + 4.375 + t2 = 0 + 4.375

Reorder the terms:
-4.375 + 4.375 + -2.5t + t2 = 0 + 4.375

Combine like terms: -4.375 + 4.375 = 0.000
0.000 + -2.5t + t2 = 0 + 4.375
-2.5t + t2 = 0 + 4.375

Combine like terms: 0 + 4.375 = 4.375
-2.5t + t2 = 4.375

The t term is -2.5t.  Take half its coefficient (-1.25).
Square it (1.5625) and add it to both sides.

Add '1.5625' to each side of the equation.
-2.5t + 1.5625 + t2 = 4.375 + 1.5625

Reorder the terms:
1.5625 + -2.5t + t2 = 4.375 + 1.5625

Combine like terms: 4.375 + 1.5625 = 5.9375
1.5625 + -2.5t + t2 = 5.9375

Factor a perfect square on the left side:
(t + -1.25)(t + -1.25) = 5.9375

Calculate the square root of the right side: 2.436698586

Break this problem into two subproblems by setting 
(t + -1.25) equal to 2.436698586 and -2.436698586.

Subproblem 1
t + -1.25 = 2.436698586

Simplifying
t + -1.25 = 2.436698586

Reorder the terms:
-1.25 + t = 2.436698586

Solving
-1.25 + t = 2.436698586

Solving for variable 't'.

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

Add '1.25' to each side of the equation.
-1.25 + 1.25 + t = 2.436698586 + 1.25

Combine like terms: -1.25 + 1.25 = 0.00
0.00 + t = 2.436698586 + 1.25
t = 2.436698586 + 1.25

Combine like terms: 2.436698586 + 1.25 = 3.686698586
t = 3.686698586

Simplifying
t = 3.686698586

Subproblem 2
t + -1.25 = -2.436698586

Simplifying
t + -1.25 = -2.436698586

Reorder the terms:
-1.25 + t = -2.436698586

Solving
-1.25 + t = -2.436698586

Solving for variable 't'.

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

Add '1.25' to each side of the equation.
-1.25 + 1.25 + t = -2.436698586 + 1.25

Combine like terms: -1.25 + 1.25 = 0.00
0.00 + t = -2.436698586 + 1.25
t = -2.436698586 + 1.25

Combine like terms: -2.436698586 + 1.25 = -1.186698586
t = -1.186698586

Simplifying
t = -1.186698586

Solution
The solution to the problem is based on the solutions
from the subproblems.
t = {3.686698586, -1.186698586}
Solution
t = {3.686698586, -1.186698586}