28 is the least common multiple. To find the least common multiple, you look through the numbers both 4 and 7 go into. The smallest of those number is the least common multiple, or LCD.
1: (-1,-1) is (x, y) to see if it is a solution, you would just plug in x and y and see if the equation is true.
-4 (-1) + 2(-1) = 2
4 + -2 = 2
2 = 2 CORRECT
So... plug in x and y in the second equation to Make sure it works for that one too.
-1 + -1 = -2
-2 = -2 CORRECT
So, yes. (-1,-1) is a solution to both equations.
Answer: q = 3
Step-by-step explanation:
Q = (21 - 15)/2 = 6/2 = 3
√(- 9 ) / (( 4 - 7 i ) - ( 6 - 6 i )) = 3 i / ( 4 - 7 i - 6 + 6 i ) =
= 3 i / ( - 2 - i ) = - 3 i / ( 2 + i ) =

=
- 1 - 2 i
Answer:
Question 1: 15 cups
20% (pineapple juice) = 3 cups, 100/20=5, 5*3 = 15 cups
Question 2: 20 cups
25% (orange juice) + 5% = 30%
30% (orange juice) = 6 cups, 30/6=5%, 100/5=20
I can't explain the whole thing very clearly, but hope it helped