Question

solve using identities 7x=45^2-25^2​

Answer 1

Answer:

7x=2025-625

7x=1400

X=1400/7

X=200

Step-by-step explanation:

Answer 2

Answer:

x = 200

Step-by-step explanation:

To find:

x, in:

7x = 45² - 25²

Method to find:

Rather than squaring both the numbers and then subtracting them, we can derive our answer using the following identity:

a² - b² = (a + b)(a - b)

So,

⇒ 7x = (45 + 25)(45 - 25)

⇒ 7x = 70 * 20

⇒ 7x = 1400

⇒ x = 1400/7

⇒ x = 200

Other identities:

• (a + b)² = a² + 2ab + b²

• (a - b)² = a² - 2ab + b²

• (x + a)(x + b) = x² + x(a + b) + ab

Hope it helps!