4. miguel asked sandra to make 90 cookies for his party. sandra needs a cup of sugar to make
15 cookies. she incorrectly calculated the amount of sugar she will need.
sandra's work:
amount of sugar for 1 cookie: 15
c = = 3.75c
amount of sugar for 90 cookies: 3.75 0.90 = 337.5 c
write a brief note to sandra describing her mistake and explain to her how to correctly
determine the amount of sugar she will need.

First, you need to divide 90 by 15, getting 6.

Then, you need to multiply 6 by 1, getting 6.

Therefore, you'll need 6 cups of sugar to make 90 cookies.

answer: the proof is mentioned below.

step-by-step explanation:

since, given:   lines bc = ef

prove:   lines ac > ef

          statements                                           reason

1. bc=ef                                           1. given

2. ac= ab+bc                                 2. because b is the point between the  

                                                            line segment ac

3.   ac > bc                                       3. because if a line segment is equal to

                                                          the sum of two line segments then it is

                                                          always greater then each of these

                                                          individual line segments

4. ac > ef                                         4. by equality property.