Answer
$5x + 2y = 250$
(0, 125), (50,0), and (20, 75) are three possible combinations
Work Step by Step
5 points per jewel and 2 points per star
250 points needed
$5x + 2y = 250$
Let x = 0:
$5x + 2y = 250$
$5*0 + 2y = 250$
$2y = 250$
$2y/2 = 250/2$
$y = 125$
Let y = 0:
$5x + 2y = 250$
$5x + 2*0 = 250$
$5x = 250$
$5x/5 = 250/5$
$x = 50$
Let x = 20:
$5x + 2y = 250$
$5*20 + 2y = 250$
$100 + 2y = 250$
$100 + 2y -100 = 250-100$
$2y = 150$
$2y/2 = 150/2$
$y = 75$
