Grant was asked to solve 49x2−225=0

by factoring using the difference of squares pattern. What is/are the correct solution(s)?(1 point)
Responses

x=−715
, x=715
x equals negative Start Fraction 7 over 15 End Fraction , x equals Start Fraction 7 over 15 End Fraction

x=−157
, x=157
x equals negative Start Fraction 15 over 7 End Fraction , x equals Start Fraction 15 over 7 End Fraction

x=−157
x equals negative Start Fraction 15 over 7 End Fraction

x=22549
, x=−22549

1 answer

To solve the equation \(49x^2 - 225 = 0\) using the difference of squares pattern, we can first recognize that this expression fits the form \(a^2 - b^2 = 0\) where:

  • \(a^2 = 49x^2\) (so \(a = 7x\))
  • \(b^2 = 225\) (so \(b = 15\))

We can rewrite the equation as:

\[ (7x)^2 - (15)^2 = 0 \]

Using the difference of squares formula, \(a^2 - b^2 = (a - b)(a + b)\), we can factor this as:

\[ (7x - 15)(7x + 15) = 0 \]

Next, we set each factor equal to zero:

  1. \(7x - 15 = 0\)
  2. \(7x + 15 = 0\)

Solving for \(x\) in each equation:

  1. From \(7x - 15 = 0\): \[ 7x = 15 \implies x = \frac{15}{7} \]

  2. From \(7x + 15 = 0\): \[ 7x = -15 \implies x = -\frac{15}{7} \]

Thus, the solutions to the equation \(49x^2 - 225 = 0\) are:

\[ x = \frac{15}{7}, \quad x = -\frac{15}{7} \]

Now, looking at the given responses, we can see that the correct solutions are:

  • \(x = -\frac{15}{7}\)
  • \(x = \frac{15}{7}\)

Therefore, the correct choice is:

x=−15/7, x=15/7.