Question

Sed
7
Three numbers are in the ratio 4 : 5: 7. If the
sum of their squares is 1440, then find the
sum of the numbers.​

Answer 1

Step-by-step explanation:

Answer:

let the common multiple be X

(4x) x (4x) + (5x) x (5x) + (7x) x (7x) = 3240

16x^2 +25x^2+49x^2 = 3240

90x^2 = 3240

x^2 = 3240/90

x^2 = 36

x =6

those numbers =

4x = 4 x 6 = 24

5x = 5 x 6 = 30

7x = 7 x 6 = 42

Answer 2

Answer:

Let the numbers be 4x ,5x ,7x then

(4x)² + (5x)² + (7x)²= 1440

16x²+25x²+49x² =1440

90x²= 1440

x² = 1440/90

x²= 16

x = root of 16 = 4

so the no.s are

4x = 4×4 =16

5x = 5×4 = 20

7x = 7×4 =28

Sum of the numbers = 16 +20 +28 = 64