Question

if three times the sum of two, number is 42 and five times their differences is 20 find the number​

Answer 1

Explanation:

let the number be x and y

3(x+y)=42

x+y=14 (42/3=14)

again, 5(x-y)=20

x-y=4

solving x+y=14

and x-y=4

x=9 and y=4

Answer 2

Answer:

$x = 9, y = 5$

Explanation:

according to question

fires condition $3(x+y) = 42$

                           $x + y = 14$   ------------------------(1)

second condition $5(x-y)=20$

                                $x-y=4$  ----------------------(2)

subtracting $eq^{n}$ (2) from $eq^{n}$ (1)

               $x+y=14$

            $-x+y=-4$

         ⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻

                    $2y = 10\\y=5$

putting value of y in $eq^{n}$ (1) gives

            $x+y=14\\x+5=14\\x=14-5\\x=9$

hence,  x = 9 and y = 5

-------------- [answered] ----------------

let's check,

we have equation,     x + y = 14

putting value of  x and y in above equation

x = 9 and y = 5 so,    9 + 5 = 14

                                  14 = 14   proved