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3 years ago

Answer this question (x −2)(x + 5) = 18

Mathematics

1 answer:

DENIUS [597]3 years ago

4 0

Answer:

x=-7 x=4

Step-by-step explanation:

(x −2)(x + 5) = 18

Foil

x^2 +5x-2x-10 = 18

Combine like terms

x^2 +3x -10 =18

Subtract 18 from each side

x^2 +3x -28 = 0

Factor

What two numbers multiply to -28 and add to 3: 7 and -4

(x+7) (x-4) =0

Using the zero product property

x+7=0 x-4 =0

x=-7 x=4

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A. A 5in radius ball is in a

abruzzese [7]

Answer:

52.33%

Step-by-step explanation:

Since, all six sides of the box are touching the ball.

So, all the three dimensions of the box are equal.

Hence, it is a cubical box.

Side length of the box (l)

= diameter of the ball

= 2*radius of the ball

= 2*5

= 10 In.

$V_{ball} = \frac{4}{3} \pi r^3$

$V_{ball} = \frac{4}{3} \times 3.14(5)^3$

$V_{ball} = \frac{4}{3} \times 3.14\times 125$

$V_{ball} = \frac{1,570}{3}\: In^3$

$V_{box} =l^3$

$V_{box} =(10)^3$

$V_{box} =1000\: In^3$

Percentage of the space in the box occupied by the ball

$= \frac{V_{ball}}{V_{box} } \times 100$

$= \frac{\frac{1,570}{3}}{1000} \times 100$

$= \frac{1570}{3000} \times 100$

$= \frac{157}{3}$

$= 52.33\%$

5 0

3 years ago

X over 2 - x over 3 = 4

Leviafan [203]

x would equal 24
24/2 - 24/3 = 4

3 0

3 years ago

The price of a coat was reduced from $40 to $30. By what percentage was the price of the coat reduced?

Liula [17]

Answer:

The percentage that the coat was reduced is 25%.

Step-by-step explanation:

A percentage is always out of a factor of 100.

40 x 2.5 = 100

30 x 2.5 = 75

75/100 = 3/4

1/4 is missing, which is the percentage.

1/4 = 0.25, or 25%

Hope This Helps!

4 0

3 years ago

Read 2 more answers

| 9. The distance between Town A and Town B was 108 km. A car and a van left Town A at 12 00 for Town B. On reaching Town B, the

Westkost [7]

Answer:

a) Time until both vehicles meet is 1.5 hours after starting at noon. That makes it 1:30PM.

b) Average speed of car is 84 km/h

Step-by-step explanation:

A -----------------------z------------B

Left Speed(km/h) Time

Car: 12PM X

Van: 12PM 60

Car/Van

DistanceCar AB + z

DistanceVan Az

Ratio: (AB+z)/Az = 7/5

Time until both meet = T (in hours)

Distance Car: xT

Distance Van: 60T

====

xT = AB + z

60T = Az

---

(xT/60T)= (7/5)

x = 60(7/5)

x = 84 km/h

=====

Time for car to reach B is: time (hr) = 108 km/(84 km/h)

time = 1.286 hours

Distance for at 1.289 hours is: distance (km) = (60 km/h)*(1.286 h)

distance = 77.14 km

At 1.286 hours, the car reverses direction. The van is (108 km - 77.14 km) or 30.86 km away.

Add the distances travelled by both vehicles after the car reverses direction at 1.286 hours. The sum will be 30.86 km when they meet, at time of T.

Car Distance + Van Distance = 30.86 km

T(84 km/h) + t(60 km)

They meet when they are 0 km apart, which can be modeled with the following equation:

Van travel Distance - Car Travel Distance = 0 starting at 1.286 hr.

Let t be the time after 1.286 hours that both vehicles meet/collide.

t*(60 km/h) + t(84 km/h) = 30.86 km

t(60+84) = 30.86 km

t(144 km/h) = 30.86 km

t = 0.2143 hr

Total time until the car and van meet is 1.286 hr + 0.2143 hr for a total of 1.50 hours.

=================

a) Time until both vehicles meet is 1.5 hours after starting at noon. That makes it 1:30PM.

b) Average speed of car is 84 km/h

==============

CHECK

Is the ratio of the distance travelled by the car and the van until they meet in the ratio of 7/5?

Car distance is (1.5 hr)(84 km/h) = 126 km

Van distance is (1.5 hr)(60 km/h) = 90.0 km

Ratio is 126/90 or 1.4

Ratio of 7/5 is 1.4

YES

3 0

2 years ago

Plzz help meeee thank you smmmmm

Slav-nsk [51]

Answer:A

Step-by-step explanation:

the y-intercept is when x-axis is 0 and that means that hours of jogging is 0 and the y-axis is 1 minunte

3 0

3 years ago

Read 2 more answers