Question

x+y=6
10y+x=10x+y= -18 find two digit number
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Answer 1

$\huge \color{orange}ANSWER:$

Let x be units digit and y be the 10s digit

10y+x = 4(x+y)

10y + x = 4x +4y

6y-3x = 0

2y - x = 0 ————-(1)

When 18 is added to the number

10y + x +18 = 10x + y

Simplify

9y - 9x = -18

y - x = - 2

y = x - 2 —————-(2)

Substitute in equation #1

2(x-2) - x = 0

2x - 4 - x=0

x = 4

Substitute in equation#2

y = 2

There for the number is

2 x 10 + 4 = 24