(25 points and brainliest) given the system of equations presented here:

4x + y = 4
2x + 7y = 28

which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated?

a. multiply the second equation by −1 to get −2x − 7y = −28
b. multiply the second equation by −4 to get −8x − 28y = −112
c. multiply the first equation by −7 to get −28x − 7y = −28
d. multiply the first equation by −2 to get −8x − 2y = −8

Marco is studying a type of mold that grows at a fast rate. he created the function f(x) = 345(1.30)x to model the number of mold spores per week. what does the 1.30 represent? how many mold spores are there after 4 weeks? round your answer to the nearest whole number. 1.30 represents the number of mold spores marco had at the beginning of the study; 985 mold spores 1.30 represents the number of mold spores grown in a given week; 448 mold spores 1.30 represents the 30% rate of weekly growth; 345 mold spores 1.30 represents the 30% rate of weekly growth; 985 mold spores

Which point lies on a circle with a radius of 5 units and center at p(6, 1)?

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum