Caprice adds equations a and b to solve this system of equations. what makes this
approach a valid method in general for solving a system of equations?
equation a: 8x + 3y = 27
equation b: 4x – 3y = 9
12x = 36

What is the number 321,000,000 in scientific notation? also what is the number? ?

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. after how many seconds will the ball hit the ground before rebounding?

Margaret is purchasing a house for $210,000 with a 15 year fixed rate mortgage at 4.75% interest she has made a 5% down payment the house is valued at 205,000 and the local tax rate is 3.5% homeowners insurance 600 per year what are her total monthly payment