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2 years ago

( x + 30 ) ( x + 40 ) solve for x

Mathematics

2 answers:

PolarNik [594]2 years ago

7 0

Answer:

Step-by-step explanation:

(x+30)(x+40)

X(x+40) +30(X+40)

X²+40x+30x+1200

X²+70x+1200

by applaying quadrtic fromula we get

a=1, b=70, c=1200

(-b ± √(b2 − 4ac))/(2a)

put the values

(-70±√(70)²-4(1)(1200)/2(1)

(-70±√4900-4800)/2

(-70±√100)/2

(-70±10)/2

either or

-70+10/2 -70-10/2

-60/2 -80/2

-30 -40

so x={-30,-40}

vazorg [7]2 years ago

5 0

Answer:

X^2 + 70x + 12000

Step-by-step explanation:

Is that what you wanted? I got that by using the distributive method.

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An airplane makes a 400-mile trip against a head wind in 4 hours. The return trip takes 2.5 hours, the wind now being a tall win

tangare [24]

Answer:

$v_p=130\ miles/h$

$v_w=30\ miles/h$

Step-by-step explanation:

Lets call $v_p$ the the still-air speed of the plane and $v_w$ the speed of the wind. On the first part the speed of the plane relative to the ground will be $v_1=v_p-v_w$ , and on the second part it will be $v_2=v_p+v_w$ .

We know that the distance d=400 miles on the first and second parts are the same, so by the definition of velocity we will have:

$v_1=\frac{d}{t1}$

$v_2=\frac{d}{t2}$

Or:

$v_p-v_w=\frac{d}{t1}$

$v_p+v_w=\frac{d}{t2}$

Adding both equations:

$(v_p-v_w)+(v_p+v_w)=2v_p=\frac{d}{t1}+\frac{d}{t2}$

$v_p=\frac{1}{2}(\frac{d}{t1}+\frac{d}{t2})$

Which for our values is:

$v_p=\frac{1}{2}(\frac{400\ miles}{4h}+\frac{400\ miles}{2.5h})=130\ miles/h$

If instead of adding, we substact, we would have:

$(v_p+v_w)-(v_p-v_w)=2v_w=\frac{d}{t2}-\frac{d}{t1}$

$v_w=\frac{1}{2}(\frac{d}{t2}-\frac{d}{t1})$

Which for our values is:

$v_w=\frac{1}{2}(\frac{400\ miles}{2.5h}-\frac{400\ miles}{4h})=30\ miles/h$

6 0

4 years ago

Marcus has $5.45. He pays $1.25 for a bus ticket. He will buy some snacks before getting on the bus. Each snack will cost $0.75.

Rom4ik [11]

1.25 + 0.75x = 5.45 <== ur equation
0.75x = 5.45 - 1.25
0.75x = 4.20
x = 4.20 / 0.75
x = 5.6.....the maximum number of snacks he can buy is 5 <==

4 0

3 years ago

Read 2 more answers

The number of subscribers y to a newspaper after t years is shown by the equation below: y = 75(0.95)t Which conclusion is corre

kodGreya [7K]

Answer:

It decreased by 5% every year

Step-by-step explanation:

When t increases by 1, the number of subscribers is multiplied by another factor of 0.95, making the new value 5% less than the previous one.

The number of subscribers decreased by 5% every year.

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3 years ago

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Cars A, B, and C are travelling at constant speeds. Select the car that travels the fastest. Choose 1 answer: Choose 1 answer: (

Gennadij [26K]

Answer:

correct answer is B

Step-by-step explanation:

comparing the speed at which the three cars travel and also considering the fact that they travel at a constant speed without increase or decrease in speed or acceleration, it gives B the highest speed at 55h per day

thank you.

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2 years ago

Please help this is URGENT

spin [16.1K]

Answer:

OPTION C: h(x) = x - 3

Step-by-step explanation:

To find the inverse of the function y = x + 3.

Swap 'x' and 'y'.

We get x = y + 3.

Solve for 'y' now.

We get y = x - 3

Therefore, the inverse function becomes h(x) = x - 3.

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3 years ago