To eliminate the terms and solve for y in the fewest steps, by which constants should the equations be multiplied by before adding the equations together? First equation: 9x + 3y = -18

Second equation: 8x + 7y = 10

A)The first equation should be multiplied by 3 and the second equation by 7.
B)The first equation should be multiplied by -3 and the second equation by -7.
C)The first equation should be multiplied by - 7 and the second equation by 3 .
D)The first equation should be multiplied by -7 and the second equation by -3.

What is the prime factorization of 23 ?me with this question

Pentagon abcde is dilated according to the rule do,3(x,y) to create the image pentagon a'b'c'd'e', which is shown on the graph. what are the coordinates of point a of the pre-image? a) (-1, 1)b) (-1, 2)c) (-9, 6)d) (-9, 18)

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect