Step-by-step explanation:
6x - 3x^2 + 2x^2 -2x = 5x^2 + 15x
4x -x^2 = 5x^2 + 15x
-11x - 6x^2 = 0
-6x^2 - 11x = 0
use the quadratic formula
(-b±√(b²-4ac))/(2a)
ANSWER
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Ratio of 8th graders to 7th graders = 3 : 2
Let the number of graders be 3x and 2x
Number of 8th graders = 18
So , 3x = 18
x = 18/3 = 6
Number of 7th graders = 2 × 6 = 12
Ratio of 6th graders to 7th graders = 5 : 4
Let the number of graders be 5a and 4a
Number of 7th graders = 12
So , 4a = 12
a = 12/4 = 3
Number of 6th graders = 5×3 = 15 ANS
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#BE BRAINLY
Answer:
6
Step-by-step explanation:
30 - 29 = 1 for the first one.
