Which equations are balanced? Select four options.

-Mg3N2 + H2O → 3MgO + 2NH3

-C3H8 + 5O2 → 4H2O + 3CO2

-Zn + 2HCl → ZnCl2 + H2

-3Ca (OH) 2 + 2H3PO4 → Ca3 (PO4) 2 + 6H2O

-3H2SO4 + 2Fe → Fe2 (SO4) 3 + H2

-4Al + 3O2 → 2Al2O3

Which expression could be used to determine the area of a rectangle with a length of 3.5 cm and a width of 0.25 cm?

If used compensation to find product of 37x4 first she found 40x4=160 then adjusted that product by adding 3 groups of 4 to get her final answer 172. What did she do incorrectly?

The figure shows an aerial view of a playground. If David runs around the field three times, he covers a distance of yards.

If a Garner has 27 pansies and 36 daisies and he plants an equal number of each for type of flower in each row what is the greatest possible number of pansies in each row

The amount of a sample remaining after t days is given by the equation (0) - A 20-4 () where A is the initial amount of the sample and h is the half-life, in days of the substance. A scientist has a 10-mg sample of a radioactive isotope.

The ratios of the number of red marbles to the number of green marbles in a bag is 2:3. The ratio of the number of green marbles to the number of blue marbles is 9:4. There are 76 marbles in the bag. Find the number of red marbles in the bag?

What is 24 (a-41) + 65 - 14

7,500,000,000 is what percent of 10,592,400,000

A new drug store is being built at the coordinates (6, 10). Is there a street parallel to (the street) that will go to the drug store? If not, what is the equation needed to put this street on the map?

Joel buys a coffee mug for 10 dollars. Sales tax is 5%. How much does Joel actually have to pay?