In 10 years, a child’s age will be 6 years less than triple her current age. Find the child’s current age.

Her current age is 8 years old.

Step-by-step explanation:

Current age: x

"In 10 years, a child’s age will be 6 years less than triple her current age."

In 10 years: x + 10

6 years less than triple: 3x - 6

x + 10 = 3x - 6

solve.

16 = 2x

x = 8

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb