Question

If the first equation is multiplied by 3 and then the equations are added, the result is _____.

3x + y = 3
x - 3y = -2

10x = 11
10x = 7
8x = 7

Answer 1

Answer:10x=7

Explanation:

Answer 2

Option B is correct.

The result is, 10x=7

Explanation:

Given the system of equation:

`3x +y =3` ......[1]

`x -3y = -2` .......[2]

As per the statement: If the first equation is multiplied by 3 and then the equations are added.

Multiply equation [1] by 3 on both sides, we get

`3(3x +y)=3\cdot 3`

Using distributive property:
`a\cdot (b+c) = a\cdot b + a\cdot c`

`9x + 3y = 9` .....[3]

Now, add equation [3] and [2], to eliminate y we get;

`9x + 3y + x - 3y = 9 -2`

`10x = 7`

Therefore, if the first equation is multiplied by 3 and then the equations are added, the result is, 10x = 7