785=3.14(10)r^2

Solution for 785=3.14(10)r^2 equation:

Simplifying
785 = 3.14(10) * r2

Multiply 3.14 * 10
785 = 31.4r2

Solving
785 = 31.4r2

Solving for variable 'r'.

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

Add '-31.4r2' to each side of the equation.
785 + -31.4r2 = 31.4r2 + -31.4r2

Combine like terms: 31.4r2 + -31.4r2 = 0.0
785 + -31.4r2 = 0.0

Add '-785' to each side of the equation.
785 + -785 + -31.4r2 = 0.0 + -785

Combine like terms: 785 + -785 = 0
0 + -31.4r2 = 0.0 + -785
-31.4r2 = 0.0 + -785

Combine like terms: 0.0 + -785 = -785
-31.4r2 = -785

Divide each side by '-31.4'.
r2 = 25

Simplifying
r2 = 25

Take the square root of each side:
r = {-5, 5}