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

How do you convert 1.27 to a percentage

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.