0=-4.9(t^2-9)+47

Solution for 0=-4.9(t^2-9)+47 equation:

Simplifying
0 = -4.9(t2 + -9) + 47

Reorder the terms:
0 = -4.9(-9 + t2) + 47
0 = (-9 * -4.9 + t2 * -4.9) + 47
0 = (44.1 + -4.9t2) + 47

Reorder the terms:
0 = 44.1 + 47 + -4.9t2

Combine like terms: 44.1 + 47 = 91.1
0 = 91.1 + -4.9t2

Solving
0 = 91.1 + -4.9t2

Solving for variable 't'.

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

Add '4.9t2' to each side of the equation.
0 + 4.9t2 = 91.1 + -4.9t2 + 4.9t2
Remove the zero:
4.9t2 = 91.1 + -4.9t2 + 4.9t2

Combine like terms: -4.9t2 + 4.9t2 = 0.0
4.9t2 = 91.1 + 0.0
4.9t2 = 91.1

Divide each side by '4.9'.
t2 = 18.59183673

Simplifying
t2 = 18.59183673

Take the square root of each side:
t = {-4.31182522, 4.31182522}