Question

Camila comprou dois livros para ler nessas férias.

Answer 1

Answer:

I will answer in English.

This can be translated to:

"Camila bought two books to read this vacation.  One is science fiction and the other is a novel.  If she finishes both books, she will have read 450 pages on vacation. The novel is known to have 60 pages  more than the science fiction book. Denoting by x  the number of pages in the fiction book and by y the number  pages of the novel book, it is possible to describe  a linear system with two equations involving x and  y with this information. "

First, the datat that we have is:

x + y = 450.

x + 60 = y.

Then we can isolate y in both equations, and have two linear equations:

y = 450 - x

y = x + 60.

Now we can graph those lines, and find the image bellow.

The point where the lines intersect is the solution of the system

We also can find the solution of the system as follows:

y = 450 - x = x + 60

then we can solve this for x.

450 - x = x + 60

2x = 450 - 60 = 390

x = 390/2 = 195

and we know that:

y = x + 60 = 195 + 60 = 255

Then: The science fiction book has 195 pages, and the novel has 255 pages.