Consider the following multistep word problem: The sum of the ages of a brother and sister is 28. If four times the brother's age is subtracted from three times the sister's age, the difference is 21.
Consider just the first sentence of this multistep word problem.
Sentence 1: The sum of the ages of a brother and sister is 28.
Give an equation that represents this statement using b as the age of the brother and s as the age of the sister.
Express your answer in terms of the symbols b and s.

Follow the steps provided in the simulation to add water to the graduated cylinder, select one of the three samples (copper, silver, or gold), set its mass to the values given in the statements below, and calculate its density. here is a summary of the steps required: add water by clicking and holding prepare a known volume of water button. until the desired volume of water has been added. if more than the desired volume is added, click the reset button. button and redo the procedure. a single click will add about 21.0 ml of water. to set the mass, click and hold weigh out metal button. until the desired amount of metal is added to the weighing pan. once the desired mass of the metal is added, release the button. transfer the metal to water and then click on calculate density button. to see how the density is calculated using water displacement to measure the volume of the solid. to save time you can approximate the initial volume of water to â±1 ml and the initial mass of the solid to â±1 g. for example, if you are asked to add 23 ml of water, add between 22 ml and 24 ml. which metals in each of the following sets will have equal density? check all that apply.

1. explain hydrogen peroxide, h 2 o 2 properties and decomposition reaction. 2. describe how each of the following natural cycles plays a part in earth’s climate system. (a) the water cycle (b) the carbon cycle

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6