How many solutions does the system of two equations shown have?
y=3(x+4)
y=3(x-4)

There is no solution. if you are using the two equations to solve for y and x.

you can plug one equations into the other.

substituting one of the y gives...
3(x+4)=3(x-4)
÷ both sides by 3 gives x+4=x-4

get x on one side and numbers on the other
x-x =4+4
and x-x will give you a 0 for the left side
therefore 0 = 4+4.. not true.

75 students decreased by 80% is 74.2