Question

an apartment complex contains 200 apartments , of these , x are 3-room apartments, and the others are 4-room apartments . how many rooms are there in the complex

Answer 1

Answer:

$(800-x)\ rooms$

Step-by-step explanation:

Let

x ----> 3-room apartments

200-x ----> 4-room apartments

we know that

To find out how many rooms are there in the complex, sum the number of 3-room apartments multiplied by 3 plus the number of 4-room apartments multiplied by 4

so

$3x+4(200-x)$

Apply distributive property

$3x+800-4x$

Combine like terms

$(800-x)\ rooms$