Solve (0.4+3b)^2=0

$$( 0.4 + 3 b ) ^ { 2 } = 0$$

Solve for b

$$b=-\frac{2}{15}\approx -0.133333333$$

Steps by Finding Square Root

Take the square root of both sides of the equation.

$$3b+0.4=0 3b+0.4=0$$

Subtract 0.4 from both sides of the equation.

$$3b+0.4-0.4=-0.4 3b+0.4-0.4=-0.4$$

Subtracting 0.4 from itself leaves 0.

$$3b=-0.4 3b=-0.4$$

Subtract 0.4 from 0.

$$3b=-0.4$$

Divide both sides by 3.

$$\frac{3b}{3}=-\frac{0.4}{3} \frac{3b}{3}=-\frac{0.4}{3}$$

Dividing by 3 undoes the multiplication by 3.

$$b=-\frac{0.4}{3} b=-\frac{0.4}{3}$$

Divide -0.4 by 3.

$$b=-\frac{2}{15}$$