20.4k views
2 votes
Let x, y, z be three natural numbers such that x < y < z. If GCF(x, y, z) = 3, GCF (y, z) = 15, LCM (x, y, z) = 3150, and x is even number greater than 10, then find the values of x, y and z.​

1 Answer

3 votes

Answer:

one of several possible solutions :

18, 75, 105

Explanation:

prime factors of 3150 :

3150 ÷ 2 = 1575

1575 ÷ 2 no

1575 ÷ 3 = 525

525 ÷ 3 = 175

175 ÷ 3 no

175 ÷ 5 = 35

35 ÷ 5 = 7

7 ÷ 5 no

7 ÷ 7 = 1

3150 = 2¹ × 3² × 5² × 7¹

these are the product of the longest streaks of prime factors in x, y and z.

the GCF(y, z) = 15.

the prime factors of 15 are simply 3¹×5¹.

so, y and z share only the factors 3 and 5.

the GCF(x, y, z) = 3.

since x is an even number, the elimination of 5 in the GCF is not surprising.

let's try the following :

x = 2¹ × 3² = 2×9 = 18

y = 3¹ × 5² = 3×25 = 75

z = 3¹ × 5¹ × 7¹ = 3×5×7 = 105

that uses all the factors of 3150, and their LCM is as the product of the longest streaks of their prime factors is

2¹ × 3² × 5² × 7¹.

fits.

the GCF(75, 105) is the product of the prime factors they have in common : 3¹ × 5¹ = 15.

fits.

the GCF(18, 75, 105) is the product of the prime factors ask 3 numbers have in common, which is only 3¹ = 3.

fits.

18 < 75 < 105

fits.

18 is an even number greater than 10.

fits.

there are more than 1 solutions.

e.g.

z = 2¹ × 3¹ × 5¹ × 7¹ = 210

is also possible.

User James Elder
by
4.3k points