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 + two-thirds) a = 50, where a is the tree's age in years. His equation is not correct. What error did he make?

Answer 1

Answer:

His error is adding 10 and 2/3 before multiplying by a(age of the tree)

Step-by-step explanation:

The sum of 10 and two-thirds of that tree's age, in years, is equal to 50.

Correct equation

Sum = addition (+)

two-thirds = 2/3

The tree's age = a

10 + 2/3a = 50

2/3a = 50 - 10

2/3a = 40

a = 40 ÷ 2/3

= 40 × 3/2

= 60

a = 60 years

Javier writes the equation

(10 + two-thirds) a = 50

(10 + 2/3)a = 50

(30+2/3)a = 50

32/3a = 50

a = 50 ÷ 32/3

= 50 × 3/32

= 150/32

a = 150/32

His error is adding 10 and 2/3 before multiplying by a(age of the tree)