In order to solve the following system of equations by addition, which of the following could you do before adding the equations so that one variable will be eliminated when you add them ? 3x -6y = -15 -2x + 5y = 14 a. multiply the top equation by 2 and the bottom one by 3. b. multiply the top equation by -3 and the bottom one by 2. c. multiply the top equation by 2. d. multiply the bottoms equation by 6.

Given abcd ac=38 and ae=3x+4 find the value of x

The edge of a cube was found to be 30 cm with a possible error in measurement of 0.4 cm. use differentials to estimate the maximum possible error, relative error, and percentage error in computing the volume of the cube and the surface area of the cube. (round your answers to four decimal places.) (a) the volume of the cube maximum possible error cm3 relative error percentage error % (b) the surface area of the cube maximum possible error cm2 relative error percentage error %

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25