algebra
posted by mag .
On a trivia game show, a contestent will answer 21 questions. A maximum of 200 points cana be earned. Some questions are worth 10 points and some are worth 8 points. Howmany of each pointvalue question must the contestent answer to earn the manimum number of points?

X 10point questions.
Y 5point questions.
Eq1: X + Y = 21 Questions
Eq2: 10x + 5y = 200 Points.
Multiply Eq1 by 5 and add Eq1 and Eq2:
5x  5y = 105
10x + 5y = 200
Solution set: (X,Y) = (19,2).
5x = 95
X = 19
In Eq1, replace x with 19:
19 + y = 21
Y = 2.