Agroup of asu sustainability student took 100 soil samples in different places in the valley. they test those samples for a certain chemical. the test is not 100% correct. if the soil contains the chemical, the test shows a positive test result 90% of the time. if the soil does not contain the chemical, it gives a negative result 80% of the time. if 20 of the soil samples contain chemicals, what is the probability the sample contains a chemical if you have a positive test return for the sample?

Amanda went into the grocery business starting with five stores. after one year, she opened two more stores. after two years, she opened two more stores than the previous year. if amanda expands her grocery business following the same pattern, which of the following graphs represents the number of stores she will own over time?

The federal reserve controls certain interest rates in the united states. investors often try to speculate as to whether the federal reserve will raise or lower rates and by how much. suppose a company conducts extensive interviews with financial analysts, and as a result, predicts that "thefed" will increase rates by an average of 0.25 percentage points every six months for the forseeable future. which type of equation could be used to model the predicted interest rates over the next several years, assuming no other significant changes? a) a linear equation b) a quadratic equation c) a polynomial equation d) an exponential equation

50 will mark show all use the linear combination method to solve the system of equations. explain each step of your solution. if steps are not explained, you will not receive credit for that step. 2x+9y= -26 -3x-7y=13