I am x years old and my brother is 7years. If you take 80% of the sum of our ages the result will be 12. Write an equation and solve it to find my age

8years

Step-by-step explanation:

I am x years old and

my brother is 7years.

The sum of our ages is (x+7)

If you take 80% of the sum of our ages the result will be 12.

80% (x+7) = 12

(80/100) (x+7) = 12

(4/5) (x+7) = 12

These is the equation (4/5) (x+7) = 12

Divide both sides by 4/5

(x+7) = 12 / (4/5) = 12 * (5/4) = 3 * 5 = 15

x+7 = 15

x = 15-7 = 8

My age is x = 8 years

And my brother is x+7 = 8+7 = 15years

Answer: you are 8 years old.

Step-by-step explanation:

You are x years old and your brother is 7years old. The sum of your ages is

(x + 7) years

If you take 80% of the sum of our ages the result will be 12. 80% of the sum of your ages is

80/100 * (x + 7) = 0.8 (x + 7)

Therefore, the equation would be

0.8 (x + 7) = 12

0.8x + 5.6 = 12

0.8x = 12 - 5.6

0.8x = 6.4

x = 6.4/0.8

x = 8 years