vi

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Phổ biến Word Problems >

3 years from now david's age will be 3 times his age 12 years ago. How old was david 12years ago

Lời Giải

3 ye a rs f ro m n o w d a v i d^{'} s a g e w i ll b e 3 t im es hi s a g e 12 ye a rs a g o . Ho w o l d w a s d a v i d 12 ye a rs a g o

Lời Giải

Davi d^{'} s age 12 years ago : 7 \frac{1}{2}

Các bước giải pháp

Translate the problem into an equation:

x + 3 = 3 (x - 12)

Giải

x, x + 3 = 3 (x - 12) : x = \frac{39}{2}

Tìm David's age 12 years ago:

7 \frac{1}{2}

Davi d^{'} s age 12 years ago : 7 \frac{1}{2}

Ví dụ phổ biến

Serenity is going to invest in an account paying an interest rate of 4.4% compounded continuously. How much would Serenity need to invest, to the nearest hundred dollars, for the value of the account to reach 670 in 11 years?One box of cereal contains 12% more cereal than another box. The larger box contains 3 more ounces of cereal than the smaller box. How much does the cereal in each box weigh?Estelle inherited some money from her grandfather and put it in a bank account that earns 9% interest compounded monthly. After 2 years, Estelle had 700.00 in the bank account. How much interest did she earn?Find the perimeter of a rectangle with a length of 9:centimeters and a width of 6 centimeters.two fair dice are rolled. what is the probability of rolling a sum between 6 and 11 exclusive