X = -3
Pull out the like terms: -7x - 21 = -7 × ( x + 3)
Solve: -7 = 0
Solve: x + 3 = 0
Subtract 3 from both sides of the equation
So, x = -3
One way to find the least common multiple of two numbers is to first list the prime factors of each number.
8 = 2 x 2 x 2
Then multiply each factor the greatest number of times it occurs in either number. If the same factor occurs more than once in both numbers, you multiply the factor the greatest number of times it occurs.
2: three occurrences
3: one occurrence
So, our LCM should be
2 x 2 x 2 x 3 = 24.
So, Marco can buy, at the very least, 24 beads of each color to have equal colors of beads.

Negative multiply negative = Positive
Negative multiply positive = negative

Thus the answer is -4a + 16b - 12c - 12d.
The distance would be 17.
all you need to do is plug the points into the distance formula.