Question

three times of a number and 4 times of another number added together makes 31
five times a number and 6 times the second number gives 49.find the numbers]

Answer 1

Answer:

let x and y be the two nos.

Step-by-step explanation:

given;

$3x + 4y = 31 - - - - - (1)$

$and \: 5x + 6y = 49$

$- - - - - (2)$

multiplying(2) by 3 and (1) by 2: we get

9x+12y=93

10x+12y=98

subtracting we get

x=5

from (1) 3x+4y=31

15+4y=31

4y=31-15

4y=16

y=4

Answer 2

Answer:

given

3x+4y = 31 ——— (1)

and

5x+6y = 49 ——— (2)

(2) - (1)

we get

5x - 3x + 6y - 4y = 49 - 31

2x + 2y = 18

x + y = 9

then x = 9 - y ———— (3)

substitute 3 in 1

27 - 3y + 4y = 31

y = 4

then,

3x + 4 ( 4) = 31

3x = 15

x = 5

therefore the numbers are 4 and 5