The sum of three numbers is 75. The third number is 2 times the first. The second number is 9 less than the first. What are the

Question

nataly862011 [7]

3 years ago

8

The sum of three numbers is 75. The third number is 2 times the first. The second number is 9 less than the first. What are the

numbers?

Mathematics

1 answer:

anygoal [31] · Answer 1 · 2022-03-18T15:34:32+03:00

anygoal [31]3 years ago

8 0

Let the three numbers be x, y and z. Then x+y+z=75.
z = 2x. y = x - 9.

Eliminate y and z by substitution: x + (x - 9) + (2x) = 75

Then 4x = 75 + 9, or 4x = 84. x = 21, y = 21 - 9 = 12, and z = 2(21) = 42.

Check: Do 21, 12 and 42 add up to 75?