how do i find the restrictions of a simplified expression? like for 4x^2-25/2x-5 what is the restriction? I know the answer which when solved is 2x+5 but where would i begin to find out the restriction?

Question

how do i find the restrictions of a simplified expression?  like for 4x^2-25/2x-5 what is the restriction?  I know the answer which when solved is 2x+5 but where would i begin to find out the restriction?

jim_thompson5910 · Answer

Rule: you cannot divide by zero

something like 1/0 is undefined

jim_thompson5910 · Answer

since 0 cannot be in the denominator, this means that 2x-5 cannot be zero

if it were zero, then 2x-5 = 0 leads to x = ???

halfdeafdarling · Answer

2x=5

halfdeafdarling · Answer

/2 ohhhh

halfdeafdarling · Answer

THANK YOU

jim_thompson5910 · Answer

5/2 or 2.5

if x = 5/2 or x = 2.5, then the denominator becomes zero. So that's why you have to place the restriction

halfdeafdarling · Answer

oh okay thank you so much that explains it much better!

jim_thompson5910 · Answer

you're welcome