Answer:
7
Step-by-step explanation:
the ratio is 3 :1
here is your answer
Answer:
33
Step-by-step explanation:
The sum of interior angles in a rectangle is 360°
98 + 98 + 98 + 2x = 360
294 + 2x = 360
2x = 66°
x = 33
Answer: the speed of the boat on the lake is 9 mph
Step-by-step explanation:
Let x represent the speed of the boat on the lake or in still water.
The speed of the current in a river is 6 mph. This means that if the boat goes upstream against the speed of the current, its total speed would be (x - 6)mph. If the boat goes downstream against the speed of the current, its total speed would be (x + 6)mph.
Time = distance/ speed
Every day, his route takes him 22.5 miles each way against the current and back to his dock, and he needs to make this trip in a total of 9 hours. This means that the time taken to travel upstream is
22.5/(x - 6). The time taken to travel downstream is
22.5/(x + 6)
Since the total time is 9 hours, it means that
22.5/(x - 6) = 22.5/(x + 6)
Cross multiplying, it becomes
22.5(x + 6) + 22.5(x - 6) = 9
Multiplying through by (x + 6)(x - 6), it becomes
22.5(x - 6) + 22.5(x + 6) = 9[(x + 6)(x - 6)]
22.5x - 135 + 22.5x + 135 = 9(x² - 6x + 6x - 36)
22.5x + 22.5x = 9x² - 324
9x² - 45x - 324 = 0
Dividing through by 9, it becomes
x² - 5x - 36 = 0
x² + 4x - 9x - 36 = 0
x(x + 4) - 9(x + 4) = 0
x - 9 = 0 or x + 4 = 0
x = 9 or x = - 4
Since the speed cannot be negative, then x = 9
Answer:
<h2>A. 4t² - 32t + 64</h2>
Step-by-step explanation:
Instead of x put (t - 3) in the equation of the function f(x) = 4x² - 8x + 4:
f(t - 3) = 4(t - 3)² - 8(t - 3) + 4
<em>use (a - b)² = a² - 2ab + b² and the distributive property a(b + c) = ab + ac</em>
f(t - 3) = 4(t² - (2)(t)(3) + 3²) + (-8)(t) + (-8)(-3) + 4
f(t - 3) = 4(t² - 6t + 9) - 8t + 24 + 4
f(t - 3) = (4)(t²) + (4)(-6t) + (4)(9) - 8t + 28
f(t - 3) = 4t² - 24t + 36 - 8t + 28
f(t - 3) = 4t² + (-24t - 8t) + (36 + 28)
f(t - 3) = 4t² - 32t + 64
