Question

Javier asks his mother how old a tree in their yard is. His mother says, “The sum of 10 and two-thirds of that tree’s age, in years, is equal to 50.” Javier writes the equation { 10 + 2/3} where a is the tree’s age in years. His equation is not correct. What error did he make?

Answer 1

"a" is not in Javier's original equation you posted..... however, the correct equation is 50 = 10 + 2a/3

a is 60 just as an FYI.

Answer 2

Answer:

Javier's equation is not correct because the variable "a" should be multiplied by $2/3$ only and then added to $10$

Step-by-step explanation:

Let

a------>is the tree’s age in years

we have that

$(10+\frac{2}{3})a=50$ -------> Javier's equation

we know that

The equation that represent the situation is equal to

$10+\frac{2}{3}a=50$

Solve for a

Multiply by $3$ both sides

$3*(10+\frac{2}{3}a)=3*50$

$30+2a=150$

$2a=150-30$

$a=120/2=60\ years$

Javier's equation is not correct because the variable "a" should be multiplied by $2/3$ only and then added to $10$