An Algebra I test contains 40 questions. Some of the q

Question

 

An Algebra I test contains 40 questions. Some of the questions are worth 4 points each, and some are worth 2 points each. The total test is worth 100 points. Let f represent the number of questions worth 4 points and t, the number of questions worth 2 points. 

Solve the system by elimination to find how many two-point questions the test contains.

Answer 1

f + t = 40

 

4f + 2t = 100

 

those are the two equations you need

 

now you can solve the system of equations by either using subsitution or elimination 

 

 

im going to use elimination multiply the first equaiton by -2

 

-2f - 2t = -80

 

then add this to the second equation  and you get 

 

 

2f = 20

 

f = 10

 

so now we can find t 

 

t = 40 - 10 = 30

 

so 30 and 10 are your values for t and f respectively anbd the number of 2 point questions are 30