What is the area of a rectangle with a width of 12 feet and length of 10 feet?, Solve: 2X+3=9 X=,?

I am doing a practice sheet for math so i can study but I am stuck on these problems can anyone who is a whiz in math help me please. solve 2/3+4/6, What would be the radius of a circle with a diameter of 8 inches? what is the perimeter of a triangle which sides measures 6,8, and 10 inches? A cube measures 3 inches on all of it's sides. What is it's volume in inches? Robert bought a used car for $1,500.00 If sales tax is 5% what is the total robert will have to pay for the car? What was the average score of all four bowlers if their scores were 132,140,145,128. I have been at this for 8 hours and cant seem to get my head on straight. Please help me.