HELP ME PLEASE !

A student solved a quadratic equation as shown here:
2x + 5x = 12
x(2x+5) = 12
x= 12or 2x+5= 12
x=12or 2x+5-5 = 12 - 5
x= 12or 2x=7
x= 12or x= 7/2
x= 7/2 , 12
Explain the errors in the process. Then correct the errors, and solve the equation.

If 1 km = 0.621 miles, how many miles are in a centimeter

The number of potato chips in a bag is normally distributed with a mean of 71 and a standard deviation of 2. approximately what percent of bags contain between 69 and 73 potato chips? approximately 68% approximately 71% approximately 95% approximately 99.7%

Amanager recorded the number of bicycles sold by his company each quarter. his projected sales after t years is given by the expression below. which of the following statements best describes the expression? a. the initial sales of 575 bicycles increases at the rate of 4% over 4 quarters. b. the initial sales of 575 bicycles increases at the rate of 18% over 4 years. c. the initial sales of 575 bicycles increases at the rate of 4% over t quarters. d. the initial sales of 575 bicycles increases at the rate of 18% over t years.