Kayla's age is 3 less than twice her brothers age. Kayla's is 13. How old is her brother?

2b - 3 = 13 So it will be 8. So her brother is 8

let x is her brother's age

Kayla's age is 3 less than twice her brothers age: 2x - 3

and

Kayla is 13

so

2x - 3 = 13

add 3 to both sides

2x - 3 + 3 = 13 + 3

simplify

2x = 16

divide both sides by 2

2x/2 = 16/2

x = 8

So her brother's age is 8 years old

proof:

2x - 3

= 2 (8) - 3

= 16 - 3

= 13