I need step by step explanation for this!

61

Step-by-step explanation:

Therefore, the number is 61

Let's check:

The sum of the two digits is 13, and we got that, so we are correct. The number is 61.

49

Step-by-step explanation:

let unit digit=x

ten's digit=y

then x+y=13

x=13-y

also x=2y+1

13-y=2y+1

13-1=2y+y

3y=12

y=12/3=4

x=13-4=9

so number =10×4+9=49

justin bieber ml.

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.