The ordered pairs are probably (0,10) and then (-1,5).
Rational due to it’s a multiple
They will ring again together at 10:15am. Because the common factor for 40, 48 and 60 is 240, which means 240 minutes, that equals to 4 hours. Hence 4 hours after 6.15am is 10.15am.
Hope this helps.
B² - 4ac
= 8² - 4*(-2)*(-9)
= 64 - 72
= -8
Angle x = 30 degrees
Angle y= 100 degrees
Angle z = 50 degrees
Sum of the angles = 180 degrees
