When a number is added to the set of numbers 7,8,9,12,6,10 and 11, the mean becomes 8. What number was added

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36

The perimeter of a rectangular lot of land is 436 ft. this includes an easement of x feet of uniform width inside the lot on which no building can be done. if the buildable area is 122 ft by 60 ft, determine the width of the easement. select one: a. 9 feet b. 18 feet c. 4.5 feet d. 7 feet

Eiko is wearing a magic ring that increases the power of her healing spell by 30%30\%30%30, percent. without the ring, her healing spell restores health points. which of the following expressions could represent how many health points the spell restores when eiko is wearing the magic ring?