Solve -7x^2+630 - ScanMath

Question

Factor the expression

- 7 (x^{2} - 90)

Evaluate

- 7 x^{2} + 630

Solution

- 7 (x^{2} - 90)

Show Solution

x_{1} = - 310, x_{2} = 310

Alternative Form

x_{1} \approx - 9.486833, x_{2} \approx 9.486833

Evaluate

- 7 x^{2} + 630

To find the roots of the expression,set the expression equal to 0

- 7 x^{2} + 630 = 0

Move the constant to the right-hand side and change its sign

- 7 x^{2} = 0 - 630

Removing 0 doesn't change the value,so remove it from the expression

- 7 x^{2} = - 630

Change the signs on both sides of the equation

7 x^{2} = 630

Divide both sides

\frac{7 x ^{2}}{7} = \frac{630}{7}

Divide the numbers

x^{2} = \frac{630}{7}

Divide the numbers

More Steps

Evaluate

\frac{630}{7}

Reduce the numbers

\frac{90}{1}

Calculate

90

x^{2} = 90

Take the root of both sides of the equation and remember to use both positive and negative roots

x = \pm 90

Simplify the expression

More Steps

Evaluate

90

Write the expression as a product where the root of one of the factors can be evaluated

9 \times 10

Write the number in exponential form with the base of 3

3^{2} \times 10

The root of a product is equal to the product of the roots of each factor

3^{2} \times 10

Reduce the index of the radical and exponent with 2

310

x = \pm 310

Separate the equation into 2 possible cases

x = 310 x = - 310

Solution

x_{1} = - 310, x_{2} = 310

Alternative Form

x_{1} \approx - 9.486833, x_{2} \approx 9.486833

Show Solution