Which expression is equivalent to this expression? (-5cd-4)(2cd2)2

It takes three hours for a boat to go 18 miles downstream, and nine hours to return. What is the rate of the boat in calm water

vampirchik [111]

Step-by-step explanation:

Distance = rate × time

If B is the rate of the boat, and C is the rate of the current, then we can write two equations:

18 = (B + C) × 3

18 = (B − C) × 9

Simplifying the equations:

6 = B + C

2 = B − C

Add the equations together to eliminate C:

8 = 2B

B = 4

Plug into either equation to find C:

C = 2

The boat's rate is 4 mph, and the current's rate is 2 mph.

5 0

3 years ago

The answer and how you got the answer

olasank [31]

Answer:

$\frac{34}{15}$

Step-by-step explanation:

we are asked to evaluate

$4\tfrac{1}{4}$ ÷ $1\tfrac{7}{8}$

Above we are given mixed fraction which can be converted in proper fraction using formula given below

$a\tfrac{b}{c}=\frac{a \times c +b}{c}$

Hence

$4\tfrac{1}{4}=\frac{4 \times 4 +1}{4}$

$4\tfrac{1}{4}=\frac{17}{4}$

Also

$1\tfrac{7}{8}=\frac{1 \times 8 +7}{8}$

$1\tfrac{7}{8}=\frac{15}{8}$

Hence

$4\tfrac{1}{4}$ ÷ $1\tfrac{7}{8}$

can be written as

$\frac{17}{4}$ ÷ $\frac{15}{8}$

Also we know the rule for dividing fraction is as given below

$\frac{a}{b}$ ÷ $\frac{c}{d}$ = $\frac{a}{b} \times \frac{d}{c}$

Hence

$\frac{17}{4}$ ÷ $\frac{15}{8}$ = $\frac{17}{4} \times \frac{8}{15}$

= $\frac{17 \times 2}{15}$

= $\frac{34}{15}$

8 0

2 years ago

Enter the correct answer in the box. solve the equation x2 − 16x 54 = 0 by completing the square. fill in the values of a and b

poizon [28]

The roots of the given polynomials exist $x=8+\sqrt{10}$ , and $x=8-\sqrt{10}$ .

<h3>What is the formula of the quadratic equation?</h3>

For a quadratic equation of the form $a x^{2}+b x+c=0$ the solutions are

$x_{1,2}=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$

Therefore by using the formula we have

$x^{2}-16 x+54=0$$

Let, a = 1, b = -16 and c = 54

Substitute the values in the above equation, and we get

$x_{1,2}=\frac{-(-16) \pm \sqrt{(-16)^{2}-4 \cdot 1 \cdot 54}}{2 \cdot 1}$$

simplifying the equation, we get

$$&x_{1,2}=\frac{-(-16) \pm 2 \sqrt{10}}{2 \cdot 1} \\$

$$&x_{1}=\frac{-(-16)+2 \sqrt{10}}{2 \cdot 1}, x_{2}=\frac{-(-16)-2 \sqrt{10}}{2 \cdot 1} \\$

$$&x=8+\sqrt{10}, x=8-\sqrt{10}$

Therefore, the roots of the given polynomials are $x=8+\sqrt{10}$ , and

$x=8-\sqrt{10}$ .

To learn more about quadratic equations refer to:

brainly.com/question/1214333

#SPJ4

3 0

1 year ago

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3/6(r-7)=1 what Is value of r

sleet_krkn [62]

3/6 (r-7) =1 The answer is r=7

3 0

2 years ago

Are 27/4 and 32/3 equivalent fractions?

Blababa [14]

Answer:

no

Step-by-step explanation:

27/4 = 54/8 = 81/12 = 108/16

= 135/20 = 162/24 = 189/28 = 216/32

= 243/36 = 270/40 = 297/44 = 324/48

= 351/52 = 378/56 = 405/60 = 432/64

= 459/68 = 486/72 = 513/76 = 540/80

= 567/84 = 594/88 = 621/92 = 648/96

= 675/100 = 702/104 = 729/108 = 756/112

= 783/116 = 810/120 = 837/124 = 864/128

= 891/132 = 918/136 = 945/140 = 972/144

= 999/148 = 1026/152 = 1053/156 = 1080/160

= 1107/164 = 1134/168 = 1161/172 = 1188/176

= 1215/180 = 1242/184 = 1269/188 = 1296/192

= 1323/196 = 1350/200 = 1377/204 = 1404/208

= 1431/212 = 1458/216 = 1485/220 = 1512/224

= 1539/228 = 1566/232 = 1593/236 = 1620/240

= 1647/244 = 1674/248 = 1701/252 = 1728/256

= 1755/260 = 1782/264 = 1809/268 = 1836/272

= 1863/276 = 1890/280 = 1917/284 = 1944/288

= 1971/292 = 1998/296 = 2025/300 = 2052/304

= 2079/308 = 2106/312 = 2133/316 = 2160/320

= 2187/324 = 2214/328 = 2241/332 = 2268/336

= 2295/340 = 2322/344 = 2349/348 = 2376/352

= 2403/356 = 2430/360 = 2457/364 = 2484/368

= 2511/372 = 2538/376 = 2565/380 = 2592/384

= 2619/388 = 2646/392 = 2673/396 = 2700/400

8 0

1 year ago

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