Solve 900=y^2

$$900 = y ^ { 2 }$$

Solve for y

$$y=30$$

$$y=-30$$

Steps Using Difference of Squares

Swap sides so that all variable terms are on the left hand side.

$$y^{2}=900$$

Subtract 900 from both sides.

$$y^{2}-900=0$$

Consider y^{2}-900. Rewrite y^{2}-900 as y^{2}-30^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).

$$\left(y-30\right)\left(y+30\right)=0$$

To find equation solutions, solve y-30=0 and y+30=0.

$$y=30 y=-30$$

Steps by Finding Square Root

Swap sides so that all variable terms are on the left hand side.

$$y^{2}=900$$

Take the square root of both sides of the equation.

$$y=30 y=-30$$

Steps Using the Quadratic Formula

Swap sides so that all variable terms are on the left hand side.

$$y^{2}=900$$

Subtract 900 from both sides.

$$y^{2}-900=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -900 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$y=\frac{0±\sqrt{0^{2}-4\left(-900\right)}}{2}$$

Square 0.

$$y=\frac{0±\sqrt{-4\left(-900\right)}}{2}$$

Multiply -4 times -900.

$$y=\frac{0±\sqrt{3600}}{2}$$

Take the square root of 3600.

$$y=\frac{0±60}{2}$$

Now solve the equation y=\frac{0±60}{2} when ± is plus. Divide 60 by 2.

$$y=30$$

Now solve the equation y=\frac{0±60}{2} when ± is minus. Divide -60 by 2.

$$y=-30$$

The equation is now solved.

$$y=30 y=-30$$