For what value of x is the expression below undefined 1-x/x+1

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Complete the steps to find 4.830 ÷ 5

Which equation shows y= 3 4 x− 5 2 in standard form? a 4x−3y=10 b 3x−4y=10 c 3x−4y=−10 d 4x−3y=−10