21. There are 80 cookies at the bakery. Each cookie is either chocolate chip or sugar cookie. There are 4 more chocolate chip cookies than 3 times the number of sugar cookies(S). How many sugar cookies are there?

Respuesta :

Answer:

[tex]19\ sugar\ cookies[/tex]

Step-by-step explanation:

Let

c------> the number of chocolate chip cookies

s-----> the number of sugar cookies

we know that

[tex]s+c=80[/tex] -----> equation A

[tex]c=3s+4[/tex] -----> equation B

substitute equation B in equation A

[tex]s+(3s+4)=80[/tex]

solve for s

[tex]4s+4=80[/tex]

[tex]4s=80-4[/tex]

[tex]s=76/4=19\ sugar\ cookies[/tex]