Question

Таблица 4на4 a+b=20,b+c=20,a+c=?

Answer 1

Ответ:20

Из 1 вычтем 2

(a+b)-(b+c)=20-20

a-c=0 отсюда следует a=c

Другими словами a+b=b+c=a+c

a=10. c=10. a+c=20

Answer 2

To solve the system of equations, let's find the values of a, b, and c. The equations are:

1. a + b = 20
2. b + c = 20

We need to find the value of a + c.

To do that, let's first find the values of a, b, and c individually:

From equation 1 (a + b = 20), we can solve for a:

1. a = 20 - b

Now, from equation 2 (b + c = 20), we can solve for c: 2. c = 20 - b

Now that we have expressions for both a and c in terms of b, let's use the information from the initial question:

a+b=20

Substitute the expression for a from equation 1 into this equation: (20 - b) + b = 20

The b term cancels out, and we are left with: 20 = 20

This equation is true, but it doesn't provide any information about the value of b. This means that there are infinitely many solutions for a, b, and c that satisfy both original equations. Therefore, we cannot determine a unique value for a + c based on the given information.

In conclusion, without additional constraints or equations, we cannot determine the value of a + c.