Respuesta :

Answer: 5x4=20

And 5+4=9

Step-by-step explanation:

The required two numbers are 4 and 5.

What is equation?

"It is a statement which consists of equal symbol between two mathematical expressions."

For given example,

We need to find two number such that if multiply then we get 20 and add to get 9.

Let 'a' and 'b' be two numbers.

According to given conditions,

a × b = 20                .........................(i)

a + b =9                    .......................(ii)

So, from given conditions we have two equations (i) and (ii).

From equation (ii) we have,

a = 9 - b                    ...............(iii)

Substitute above value of 'a' in equation (i),

⇒ (9 - b) × b = 20

⇒ 9b - b² = 20

⇒ b² - 9b + 20 = 0

Now we solve this quadratic equation to find b.

⇒ b² - 9b + 20 = 0

⇒ b² - 5b - 4b + 20 = 0

⇒ (b - 5) (b - 4) = 0

⇒ b = 5 or   b = 4

Find the value of 'a' from equation (iii)

When b = 5

⇒ a = 9 - 5

⇒ a = 4

When b = 4

⇒ a = 9 - 4

⇒ a = 5

Therefore, the required two numbers are 4 and 5.

Learn more about equation here:

https://brainly.com/question/13170101

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