2.14x - 12.18 = -5.76
add 12.18 to both sides:
2.14x = 6.42
divide both sides by 2.14
x= 3
The next number is 77040. Solution: 107 x 2 = 214x 3 = 642 x 4 = 2568 x 5 = 12840 x 6 = 77040
Call the shorter piece 'x'.The longer piece is (3x+1), you said so yourself.They add up to 21 feet. (You said "together"; I have to assume that means "end-to-end".)x + (3x + 1) = 21x + 3x + 1 = 214x + 1 = 214x = 20x = 53x + 1 = 16The lengths of the pieces are 5-ft and 16-ft.================================Check:Is (5 + 16) = 21 ?Yes.Is (16) = (3 x 5) + 1 ?Yes.Yay !