6x-15y=-63
-15x+15y=90
This is because you are multiplying the first equation by a constant of 3 and the second equation by 5 so that you can have -15y and +15y which will cancel each other out.
8.8-3.4=5.4
Just subtract 8-3 and 8-4 and you'll get 5.4
Hope it helps!

Brainliest please if you found my answer helpful! :)
Answer:
12 and 28 is 4 next one is 375x2y then 588m2n2
Step-by-step explanation:
Answer:
Scalene is the right option.
Step-by-step explanation:
A scalene triangle has all its sides of different lengths.
The answer is D. No relationship but there’s no question for it so it maybe wrong