Answer:
55 mph
Step-by-step explanation:
Let x represent Bob's speed. Then John's speed is x+10, and their respective times are found by ...
time = distance/speed
330/x = 390/(x+10) . . . . . . . the times are the same
330(x +10) = 390x . . . . . . . multiply by x(x+10)
3300 = 60x . . . . . . . . . . . . . subtract 330x
55 = x . . . . . . . . . . . . . . . . . . divide by the coefficient of x
Bob is driving at 55 miles per hour.
B) square root 62 inches
C) square root 128 inches
Descarte's Rule of Sign is useful for finding the zeroes of a polynomial. The rule will tell you how many roots you can expect and of which type not where the polynomial's zeroes are. This rule is given as follows:
That is, the function:
4, 2, or 0 positive roots
On the other hand, the function:
2, or 0 negative roots
Finally:
Complex roots: 0, 2, 4, or 6