An artist is using 2 different colors in a mosaic. The ratio of green to blue is 3:6 . If she has 21 green tiles to use, how many blue tiles does she have?

Which of the following equations are equivalent to -2m - 5m - 8 = 3 + (-7) + m? -15m = -4m -7m - 8 = m - 4 -3m - 8 = 4 - m m - 4 = -7m - 8 -8 - 7m = -4 + m -8 - 3m = 4 - m