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3 years ago

The sum of the digits of a certain two-digit number is 11. When you reverse its digits you increase by 9. What is the number?

1 answer:

8 0

The number is composed by two digits, let them be ab, so we have:
a + b = 11

this is a pseudo-equation, we are not multiplying ab or ba, is just the digits order.
ba = ab + 9
The pairs of numbers that could comply with the first equation are:
(2,9)
(3,8)
(4,7)
(5,6)
But only the last couple (5,6) comply as well with the second condition. Because 65 = 56 + 9
Therefore the unknown number is 56

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Sarah is saving money to buy a microscope. She has saved $25 so far. That's 1/3 of the

seropon [69]

Answer:

X = $75

Step-by-step explanation:

X=total cost

x* (1/3) =$25

multiply by 3 on both sides

x=$75

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2 years ago

A central angle theta in a circle of radius 7 m is subtended by an arc of length 8 m. Find the measure of theta in degrees. (Rou

gogolik [260]

Answer: In degrees , The measure of $\theta=65.5^{\circ}$

In radians , the measure of $\theta =\dfrac{8}{7}\text{ radians}$ .

Step-by-step explanation:

We know that the formula for length of arc is given by :-

$l=\theta r$

, where $\theta$ = Central angle subtended by arc.

r= radius of the circle.

As per given , we have

Radius of circle : r=7 m

Length of arc : l= 8 m

Substitute these values in the above formula , we get

$8=\theta (7)\\\\\Rightarrow\ \theta =\dfrac{8}{7}\text{ radians}$

Hence, the measure of $\theta =\dfrac{8}{7}\text{ radians}$ .

To convert it into degrees we multiply it with $\dfrac{180^{\circ}}{\pi}$

The measure of $\theta =\dfrac{8}{7}\times\dfrac{180^{\circ}}{\pi}$

$=(\dfrac{8\times180}{7\times3.14})^{\circ}=65.5141037307^{\circ}$

$\approx65.5^{\circ}$

Hence, the measure of $\theta=65.5^{\circ}$

8 0

3 years ago

An anthropologist studies a woman's femur that was uncovered in Madagascar. To estimate the woman's height, he uses the equation

Lelu [443]

Answer:

The inequality $f>40$ represents the length of the femur for which the woman had a height greater than 160cm.

Step-by-step explanation:

The given equation is

$h=60+2.5f$

Where, h is woman's height in centimeters and f is length of the femur in centimeters.

If woman's height is greater than 160cm, then

$h>160$

$60+2.5f>160$

Substract 60 from both sides.

$2.5f>100$

Divide both sides by 2.5.

$f>40$

Therefore the inequality $f>40$ represents the lengths of the femur for which the woman had a height greater than 160cm.

5 0

3 years ago

What times 2 equals -3?

Xelga [282]

Answer:

just form an equation

let that number be x

then 2x=-3

x=-3/2 ANSWER

6 0

2 years ago

Read 2 more answers

Of 30 students 1/3 play sports 2/3 of them play soccer. How many play soccer

agasfer [191]

1/3 of 30 is 10 because you dividing it by 3 and you would get 10.

Now 2/3 of 10 :

10/3=3.3 (2/3 so we have to multiply by 2) 3.3•2=6.6

6.6 has to be estimated because you can't have 6.6 people.

Your answer would be 6. Before I said 7 but you said I was incorrect so the only possibility left is 6.

Hoped I helped!

4 0

3 years ago

Read 2 more answers