If 2x + 3y + z = 55, x + z – y = 4 and y – x + z = 12, then what are the values of x, y and z?
Answer
Answer (as printed):
Explanation
The given equations are: 2x + 3y + z = 55 ...(i); x + z – y = 4 ...(ii); y – x + z = 12 ...(iii) Subtracting (ii) from (i), we get: x + 4y = 51 ...(iv) Subtracting (iii) from (i), we get: 3x + 2y = 43 ...(v) Multiplying (v) by 2 and subtracting (iv) from it, we get: 5x = 35 or x = 7. Putting x = 7 in (iv), we get: 4y = 44 or y = 11. Putting x = 7, y = 11 in (i), we get: z = 8.
Explanation as extracted from the printed page; notation may be imperfect.