solve a system of equation by substition

[bobisaka]

How did they get 16/2??

I get:
(15/4)-(-1/2)=8
(15/4)-1(-1/2)=8
(15/4)(1/2)=8 <================ I am confused at this point by which strategy to use?

I don't know how they simplified it to 16/2 = 8


EDIT:

After redoing it, is there a typo in the textbook?

It should be the following: (15/2) + (1/2) = 8

 

[nasi112]

(-)(-) = +
means
negative times negative = positive

[MATH]\frac{15}{2} - \frac{-1}{2} = \frac{15}{2} + \frac{1}{2} = \frac{16}{2} = 8[/MATH]

 

[bobisaka]

(-)(-) = +
means
negative times negative = positive

[MATH]\frac{15}{2} - \frac{-1}{2} = \frac{15}{2} + \frac{1}{2} = \frac{16}{2} = 8[/MATH]

I get that, If you look back at my post edit, there is a typo in the textbook which confused me.

Correct me I am wrong.

 

[Deleted member 4993]

View attachment 25711

How did they get 16/2??

I get:
(15/4)-(-1/2)=8
(15/4)-1(-1/2)=8
(15/4)(1/2)=8 <================ I am confused at this point by which strategy to use?

I don't know how they simplified it to 16/2 = 8


EDIT:

After redoing it, is there a typo in the textbook?

It should be the following: (15/2) + (1/2) = 8

You are correct here - and -

there is a typo in the book, as you indicated.