To find their average miles per hour we can divide the total miles by the hour used:
4 2/3 ÷ 1 2/3
=4x3+2/3 ÷ 1x3+2/3
=14/3 ÷ 5/3
In division, when we switch the place of numerator and denominator, we can change it to multiplication which makes the calculation easier as we can factorize the numbers.
=14/3 x 3/5
Factorize 3 in both amounts:
=14/1 x 5/1
=14/5
=2.8 miles/hour
Therefore their average speed is 2.8 miles/hour.
Hope it helps!
Answer:
x = - 2.5
Step-by-step explanation:
Given that the sketch represents
y = x² + bx + c
The graph crosses the y- axis at (0 , - 14), thus c = - 14
y = x² + bx - 14
Given the graph crosses the x- axis at (2, 0), then
0 = 2² + 2b - 14
0 = 4 + 2b - 14 = 2b - 10 ( add 10 to both sides )
10 = 2b ( divide both sides by 2 )
b = 5
y = x² + 5x - 14 ← represents the graph
let y = 0 , then
x² + 5x - 14 = 0 ← in standard form
(x + 7)(x - 2) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
x - 2 = 0 ⇒ x = 2
The x- intercepts are x = - 7 and x = 2
The vertex lies on the axis of symmetry which is midway between the x- intercepts, thus
the x- coordinate of the turning point is
=
= - 2.5
He traveled 2080 miles after 4 hours. He covered 3640 miles in 7 hours with a constant speed, so we can calculate the speed: 3640/7=520 miles/hour. After 4 hours, he traveled 520*4=2080 miles.
Step-by-step explanation:
