Achef bought some green and red peppers. she bought 18 green peppers, which was 3/4 the total number. how many red peppers did she buy? how many peppers did she buy altogether?

 She bought 6 (six) red peppers.  She bought 24 peppers altogether.

Explanation:

Let "y" = the total number of peppers.

(3/4)y = 18 = number of green peppers.

y = 1y = (4/4)y = total number of peppers.

So (4/4)y  − (3/4)y = (1/4) y = number of red peppers.

If, (3/4)y = 18;  solve for "y" ;

    →  Given:   (3/4)y = 18 ;   

    →  Multiply EACH side of the equation by "4"; to get rid of the fraction;

    →   4* (3/4)y = 18 * 4 ;

    →  3y = 72 ;

Divide EACH side of the equation by "3" ; to isolate "y" on one side of the equation; and to solve for "y" ; 

    →  3y / 3 = 72 / 3 ;
 
    →     y  = 24 ;                      

So, the total number of peppers = y = 24 peppers.

We are given the number of green peppers = 18 green peppers.

The number of red peppers = 24 − 18 = 6 red peppers.

Also, the number of red peppers should equal: (1/4)*y ; which should equal: "6".    (1/4)*y = (1/4)*24 =? 6 ?  Yes!  So, there are 6 red peppers.

 She bought 6 (six) red peppers.  She bought 24 peppers altogether.