Find the scale factor

I think its 1.4

Step-by-step explanation:

if you divide 42 by 1.4 it makes 30 and if u multiply 30 by 1.4 it makes 42

the scale factor is 7/5

Step-by-step explanation:

42/30=

42/30=

then you find a common factor between the two is 6, so you divide both sides of the fraction by 6 to get 7/5. and because they both are the same you know that they both have the same scale factor. Which is 7/5. I am not quite sure if you need to find the missing side length but in case you do multiply 40 by 7/5 so it looks like 40/1 x 7/5. 40 x 7 = 280. 280/5 = 56. so your side length is 56.

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer