Question

4. Kiran says that a solution to the equation x + 4 = 20 must also be a solution to the equation 5(x + 4) = 100. Write a convincing explanation as to why this is true.​

Answer 1

Kiran is correct. To see why, let's first simplify the second equation, 5(x + 4) = 100, by multiplying both sides by 1/5:

5(x + 4) = 100

⇒ (1/5) * 5(x + 4) = (1/5) * 100

⇒ x + 4 = 20

Now we can see that the second equation simplifies to the first equation, x + 4 = 20. This means that any solution that satisfies the first equation (x + 4 = 20) will also satisfy the second equation (5(x + 4) = 100).

In other words, if we find a value of x that makes x + 4 = 20 true, then substituting that value of x into 5(x + 4) = 100 will also make it true. Therefore, any solution to the equation x + 4 = 20 will also be a solution to the equation 5(x + 4) = 100.

Explanation:

Answer 2

Kiran is correct in saying that a solution to the equation x + 4 = 20 must also be a solution to the equation 5(x + 4) = 100. This is because the second equation is simply the first equation multiplied by 5. To see this, we can distribute the 5 on the left side of the second equation to get 5x + 20 = 100. We can then subtract 20 from both sides to get 5x = 80, and finally divide both sides by 5 to get x = 16.

Since x = 16 satisfies the first equation, it must also satisfy the second equation. This is because if we substitute x = 16 into the first equation, we get 16 + 4 = 20, which is true. If we substitute x = 16 into the second equation, we get 5(16 + 4) = 100, which is also true. Therefore, any solution to the first equation will also be a solution to the second equation when the second equation is just the first equation multiplied by a constant factor.