Please help me for my practice problems

Blank × 10-3 is 2,000 times greater than 1.9 × 10-6. it is also blank times greater than 9.5 × 10-4.

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14

What are the greatest common factor of 75 and 30