Question

comic books cost $2 each and magazines cost $4 each. if you want to spend exactly $30 and you buy 7 comic books, how many magazines can you buy? youre trying to figure out how many magazines you can buy if you buy 7 comic books, and want to spend exactly $30. c represents the number of comic books, so start by substituting 7 for c in the equation. 2c + 4m = 30 2·□ + 4m = 30

Explanation:

Step1: Substitute c=7 into equation

$2 \cdot 7 + 4m = 30$

Step2: Calculate 2 times 7

$14 + 4m = 30$

Step3: Isolate the term with m

$4m = 30 - 14$
$4m = 16$

Step4: Solve for m

$m = \frac{16}{4}$

Answer:

$m=4$
The number of magazines you can buy is 4, and the value to fill in the square is 7.