Question

The sum of three numbers is 69. The second number is equal to the first diminished by 8, and the third number is 5 times the first.

If x represents the first number, then which of the following equations could be used to determine the values of all of the numbers?

x = 6x - 8
69 = 6x - 8
69 = 7x - 8

Answer 1

7x - 8 = 69, can be used to determine the values of all of the numbers.

Step-by-step explanation:

Let, three number be x, y and z.

It is given that the sum of all three is 69.

• x + y + z = 69  ........(1)

According to the question, the second number is equal to the first diminished by 8.

• So, y = x - 8 ............(2)

And, The third number is 5 times the first.

• So, z = 5x    ............(3)

Put the values of y & z from (2) & (3) respectively in equation (1), we get,

• x + x - 8 + 5x = 69

                    7x - 8 = 69     ...........(4)

Thus, the equation (4), we can used to determine the values of all of the numbers.