Answer:
Step-by-step explanation:
chiều dài:x,x>0
chiều rộ:y
Http://www.allthetests.com/quiz30/quiz/1379266484/Does-He-Like-you-Back-10-13-year-olds-ONLY
For 5a+5b+5c=-20
A= -4 - b - c
B= -4 - a - c
C= -4 - a - b
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4a+3b+3c=-6
A= -3/2 - 3b/4 - 3c/4
B= -2 - 4a/3 - c
C= -2 - 4a/3 - b
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-4a+3b+3c=9
A= -9/4 + 3b/4 + 3c/4
B= 3 + 4a/3 - c
C= 3 + 4a/3 - b
5(x + 2/3) = 3x - 2/3.....distribute the 5 through the parenthesis
5x + 10/3 = 3x - 2/3 ....subtract 3x from both sides
5x - 3x + 10/3 = 3x - 3x - 2/3...combine like terms
2x + 10/3 = - 2/3 ....subtract 10/3 from both sides
2x + 10/3 - 10/3 = -2/3 - 10/3...simplify
2x = - 12/3....reduce
2x = - 4....divide both sides by 2
x = -4/2....reduces to -2
or this way...
5(x + 2/3) = 3x - 2/3.....distribute
5x + 10/3 = 3x - 2/3....multiply by lowest common denominator of 3
15x + 10 = 9x - 2 ....subtract 9x from both sides
15x - 9x + 10 = -2 ...subtract 10 from both sides
6x + 10 - 10 = -2 - 10...simplify
6x = -12.....divide both sides by 6
x = -12/6 reduces to -2
The synodic month, or complete cycle of phases of the Moon as seen from Earth, averages 29.530588 mean solar days in length (i.e., 29 days 12 hours 44 minutes 3 seconds); because of perturbations in the Moon’s orbit, the lengths of all astronomical months vary slightly. The sidereal month is the time needed for the Moon to return to the same place against the background of the stars, 27.321661 days (i.e., 27 days 7 hours 43 minutes 12 seconds)
