Question

1. Brady’s age is four less than twice that of his brother. When you add Brady and his brother’s ages, you get 20. How old is each of the boys?

(a) Write an equation that represents the situation. Explain any variable used.
(b) Solve the equation from Part (a). Show your work. State your solution as a complete sentence.
Answer:

Answer 1

I think Brady is 12 and his brother is 8.

a: (20-4)/2=8 for his brother and next you do 20-8=12 for Brady's age

b: Brady is 12 years old and his brother is 8.

Explanation:

Answer 2

b = brady
x = brother

b = 2x - 4
b + x = 20

We’ll take the expression b = 2x - 4 and drop it I to the second equation to solve for x

2x - 4 + x = 20
3x - 4 = 20
3x = 24
x = 8

So that means 20 - 8 = b, b = 12

Checking the math: 12 = 2(8) -4, 12 = 16-4, 12 = 12

Brady’s brother is 8 years old, and Brady is 12 years old.