Question 174906
Let x = the number of 2-point questions
Let y = the number of 5 point questions

x + y = 38 (There are 38 total questions)(Equation #1)

x*2 + y*5 = 100 (The total number of points is 100) (Equation #2)

Equation #1 can be rewritten as y = 38-x

This can be used to replace "y" in equation #2

So 2*x + 5*(38-x)=100

So 2*x+190-5*x=100

Therefore -3*x=100-190=-90

Solve  -3*x = -90 for x by dividing each side of the equation by 3, x = 30

Since x = 30, y = 38-30 = 8 (Using equation #1)

I hope that this helps.