The sum of three numbers is 18. The sum of twice the first number, 4 times the second number, and 5 times the third number is 60. The 差 between 7 times the first number and the second number is 50. Find the three numbers.

解

T h e s u m o f t h ree n u mb ers i s 18. T h e s u m o f tw i ce t h e f i rs t ​ n u mb er, 4 t im es t h e seco n d ​ n u mb er, an d 5 t im es t h e t hi r d n u mb er i s 60. T h e d i ff ere n ce b e tw ee n 7 t im es t h e f i rs t n u mb er an d t h e seco n d n u mb er i s 50. F in d t h e t h ree n u mb ers .

The numbers : 8, 6, 4

解答ステップ

Represent the numbers with

x, y, z

number 1 : x

number 2 : y

number 3 : z

A.T.Q.:

x + y + z = 18

2 x + 4 y + 5 z = 60

7 x - y = 50

x + y + z = 18, 2 x + 4 y + 5 z = 60, 7 x - y = 50 : x = 8, y = 6, z = 4

The numbers : 8, 6, 4