Question

What must be added to: (a) x-y + 4z to get 5x - 4y + 8z?​

Answer 1

4x - 3y + 4z

Explanation:

Let the unknown value that we have to add be 'a'.

Let us make an expression like this.

x -y + 4z + a = 5x - 4y + 8z

Now make 'a' the subject of the equation.

a = 5x - 4y + 8z - x + y - 4z

Now combine like terms.

a = 5x - x - 4y + y + 8z - 4z

a = 4x - 3y + 4z

Now let us check whether the answer is correct or wrong.

We can replace 'a' with ( 4x - 3y + 4z ).

Let us see.

x - y + 4z + 4x - 3y + 4z

Combine like terms.

5x - 4y + 8z

Yes, we are getting the same answer!

Therefore,

we need to add 4x - 3y + 4z to get 5x - 4y + 8z to x - y + 4z.

Answer 2

4x-3y+4z

Explanation:

There are lot's of process to answer it but i will show one easy way to find the answer.

To find the required answer we need to subtract 5x - 4y + 8z by x-y + 4z, we get

5x - 4y + 8z

-x + y - 4z [Note: while subtracting we must change the sigh that one ___________who we are subtracting]

4x-3y+4z which is a required answer