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2 years ago

What's 57.8 divided by 81 using compatible numbers?

Mathematics

1 answer:

Arisa [49]2 years ago

7 0

you can estimate 57.8 and 81 then to check you can do 57.8 divided by 81

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Solve ax + b = cx + d for x.

romanna [79]

Answer: X = (d-b) / (a-c)

This way this worded is weird but I think I got it

Step-by-step explanation:

Subtract B from both sides

ax = cx +d -b

Then subtract CX from both sides

ax -cx =d-b

Distributive Property

x(a-c) =d-b

Divide both sides by a-c

X = (d-b) / (a-c)

6 0

2 years ago

A man starts walking north at 2 ft/s from a point P. Five minutes later a woman starts walking south at 3 ft/s from a point 500

Vedmedyk [2.9K]

Answer:

The rate at which both of them are moving apart is 4.9761 ft/sec.

Step-by-step explanation:

Given:

Rate at which the woman is walking, $\frac{d(w)}{dt}$ = 3 ft/sec

Rate at which the man is walking, $\frac{d(m)}{dt}$ = 2 ft/sec

Collective rate of both, $\frac{d(m+w)}{dt}$ = 5 ft/sec

Woman starts walking after 5 mins so we have to consider total time traveled by man as (5+15) min = 20 min

Now,

Distance traveled by man and woman are $m$ and $w$ ft respectively.

⇒ $m=2\ ft/sec=2\times \frac{60}{min} \times 20\ min =2400\ ft$

⇒ $w=3\ ft/sec = 3\times \frac{60}{min} \times 15\ min =2700\ ft$

As we see in the diagram (attachment) that it forms a right angled triangle and we have to calculate $\frac{dh}{dt}$ .

Lets calculate h.

Applying Pythagoras formula.

⇒ $h^2=(m+w)^2+500^2$

⇒ $h=\sqrt{(2400+2700)^2+500^2} = 5124.45$

Now differentiating the Pythagoras formula we can calculate the rate at which both of them are moving apart.

Differentiating with respect to time.

⇒ $h^2=(m+w)^2+500^2$

⇒ $2h\frac{d(h)}{dt}=2(m+w)\frac{d(m+w)}{dt} + \frac{d(500)}{dt}$

⇒ $\frac{d(h)}{dt} =\frac{2(m+w)\frac{d(m+w)}{dt} }{2h}$ ...as $\frac{d(500)}{dt}= 0$

⇒ Plugging the values.

⇒ $\frac{d(h)}{dt} =\frac{2(2400+2700)(5)}{2\times 5124.45}$ ...as $\frac{d(m+w)}{dt} = 5$ ft/sec

⇒ $\frac{d(h)}{dt} =4.9761$ ft/sec

So the rate from which man and woman moving apart is 4.9761 ft/sec.

3 0

3 years ago

What is in (e^A)? A, A+1, ln A + ln e, 1 + ln A

nata0808 [166]

Answer:

$\large\boxed{\ln e^A=A}$

Step-by-step explanation:

$Use\\\\\log_ab^n=n\log_ab\\\\\log_aa=1\\\\\ln a=\log_e a\to\ln e=1\\====================================\\\\\ln e^A=A\ln e=A(1)=A$ [/tex]

5 0

3 years ago

I have 8 squares and 7 are shaded in. write the unit fraction that represents each part of the whole. next write the number of s

sammy [17]

There is 8 sq so it's going to be a denominator. Since there is 8 sq if you take 1 away it will be 7, 7 is shaded. 1 will be the numerator.

6 0

2 years ago

A shop has an offer on jumpers as shown below.

KatRina [158]

Answer: £6.80

Step-by-step explanation:

Kara bought 5 jumpers for the price of 4. Thus, multiply 4.8*5 = 24. Then divide 24/4 to get 6.

Hope it helps <3

6 0

3 years ago

Read 2 more answers