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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

Mathematics
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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What is the value of 7+z divide by 2 when z=10
amm1812
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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}

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On comparing both sides, we get

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8-3a=2

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3 0
2 years ago
Help asap thank you .
frosja888 [35]

Answer:

2

Step-by-step explanation:

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Alex_Xolod [135]

Answer:

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Step-by-step explanation:

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Height of cone is 75 ft.

Circumference of base is :

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

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