How do I find X for (A+B) X=C-X?

Question

Please help. I don’t understand this at all. I’m trying so hard

Answer 1

Dear Tijana

You have to follow these steps:

Step 1 Multiply each term inside the brackets by the unknown X in the left side

(A + B) X = C - X

AX + BX = C - X

Step 2 Pass to the left side all the terms having the unknown X and change its sign

AX + BX = C - X

AX + BX + X = C

Step 3 Add all the terms having the unknown X

AX + BX + X = C

(A + B + 1) X = C

Step 4 Pass the coefficients multiplying the unknown X to the right side by dividing the term C

X = C / (A + B + 1)