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PilotLPTM [1.2K]

3 years ago

12

the sum of the digits of a certain two-digits number is 7.Reversing its digits increases the number by 9.What is the number

2 answers:

rusak2 [61]3 years ago

8 0

Unit digit=y
tens digit=x
the number: 10x+y

We suggest this system of equations:
x+y=7
(10y+x)=(10x+y)+9
we solve it by substitution method.
x=7-y
10y+(7-y)=(10(7-y)+y)+9
9y+7=70-10y+y+9
9y+10y-y=70+9-7
18y=72
y=72/18=4

x=7-y
x=7-4=3

number=10x+y=10*3+4=30+4=34

solution: the number: 34

To check:
3+4=7
43=34+9

dimaraw [331]3 years ago

7 0

The answer is 34. 3+4=7. 43-34=9. I hope this helps.

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Write this number in expanded form using fractions and decimals 0.362

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2 years ago

Read 2 more answers

What is the value of 7+z divide by 2 when z=10

amm1812

The answer to your question is 8.1

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3 years ago

3<br>Find the value of a <br>in the equation,(3+4√3)(2-a√3)=-18+2√3

ankoles [38]

Given:

The equation is:

$\left(3+4\sqrt{3}\right)\left(2-a\sqrt{3}\right)=-18+2\sqrt{3}$

To find:

The value of a.

Solution:

We have,

$\left(3+4\sqrt{3}\right)\left(2-a\sqrt{3}\right)=-18+2\sqrt{3}$

On simplification, we get

$(3)(2)+(4\sqrt{3})(2)+(3)(-a\sqrt{3})+(4\sqrt{3})(-a\sqrt{3})=-18+2\sqrt{3}$

$6+8\sqrt{3}-3a\sqrt{3}-4a(3)=-18+2\sqrt{3}$

$6+8\sqrt{3}-3a\sqrt{3}-12a=-18+2\sqrt{3}$

$(6-12a)+(8-3a)\sqrt{3}=-18+2\sqrt{3}$

On comparing both sides, we get

$6-12a=-18$

$-12a=-18-6$

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$a=2$

And,

$8-3a=2$

$-3a=2-8$

$a=\dfrac{-6}{-3}$

$a=2$

Therefore, the value of a is 2.

3 0

2 years ago

Help asap thank you .

frosja888 [35]

Answer:

2

Step-by-step explanation:

count up 2 count right 1, 2/1

2/1 = 2

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2 years ago

What is the volume of a right circular cone if the circumference of the base is 125.6 ft and the height is 75 ft.? Use π=3.14 an

Alex_Xolod [135]

Answer:

The volume of a right circular cone is $31400\ \text{feet}^3$ .

Step-by-step explanation:

The circumference of the base of a right circular cone is 125.6 ft.

Height of cone is 75 ft.

Circumference of base is :

$C=2\pi r$ , r is radius

$r=\dfrac{C}{2\pi}\\\\r=\dfrac{125.6}{2\times 3.14}\\\\r=20\ ft$

The volume of a cone is given by :

$V=\dfrac{1}{3}\pi r^2 h\\\\V=\dfrac{1}{3}\times 3.14\times (20)^2\times 75\\\\V=31400\ \text{feet}^3$

So, the volume of a right circular cone is $31400\ \text{feet}^3$ .

5 0

3 years ago