Question

PLS HURRY HAVE 10MIN. LEFT

the unit digit of a 2 digit number is 5 more than the tens diget and the number itself is 3 times the sum of the digits. find the NUM

Answer 1

Here the equations are if the digits be a and b

• b=a+5--(1)

3(a+b)=10a+b

• 3a+3b=10a+b
• 7a=2b
• b=7/2a--(2)

Equate both

• 7a/2=a+5

• 7a=2a+10
• 5a=10
• a=2

And

• b=2+5=7

The number is 27

Answer 2

• 27

Explanation:

Let the tenth digit is x and units digit is y.

We have the following equations:

• y = x + 5
• (x + y)*3 = 10x + y

Simplify the second equation:

• 3x + 3y = 10x + y
• 2y = 7x

Solve by substitution:

• 2(x + 5) = 7x
• 2x + 10 = 7x
• 7x - 2x = 10
• 5x = 10
• x = 2

Find y:

• y = 2 + 5
• y = 7

The number is 27