Ryan bought 3 books and a magazine . he paid $30 and relieved $5 change if the magazine cost twice as much as each book, find the cost of the magazine.
explain in algebra only : )

 The required cost of the magazine is $10.

Step-by-step explanation:  Given that Ryan bought 3 books and a magazine. He paid $30 and relieved $5 change and the magazine cost twice as much as each book.

We are to find the cost of the magazine.

Let x and y represents the cost of a book and the magazine respectively.

Then, according to the given information, we have

and

Substituting the value of y from equation (ii) in equation (i), we get

and from equation (ii), we get

Thus, the required cost of the magazine is $10.

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct

use distributive property on all like terms and change your signs if you have a double negative or if you have positive/negative