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3 years ago

I am thinking of a number. If you add 3 to the number and then multiply the sum by four, you end up with 48. What is my number?

Mathematics

1 answer:

kap26 [50]3 years ago

5 0

Answer:

Step-by-step explanation:

48 / 4 = 12

12 - 3 = 9

Check Work

9 + 3 = 12

12 * 4 = 48

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Ava worked 40 hours this week and made $520. How much did he earn each hour?

Blababa [14]

He made $13.00 an hour. Hope this helps! :)

4 0

3 years ago

5x^2 + 19x + 12=0<br> how do i figure this out

zlopas [31]

Answer:

x=−4/5 or x=−3

Step-by-step explanation:

Step 1: Factor left side of equation.

(5x+4)(x+3)=0

Step 2: Set factors equal to 0.

5x+4=0 or x+3=0

x=−4/5 or x=−3

3 0

2 years ago

The sum of the digits of a 2-digit number is 10. If 18 is added to the number, the digits of the new number are those of the ori

Aliun [14]

Answer:

Step-by-step explanation:

Let $(ab)$ represent a number with $a$ in the ten's position and $b$ is the one's position.

This means $(ab)$ actually has value of $10a+b$ .

We are given the sum of those digits of $(ab)$ is 10; this means $a+b=10$ .

It says if 18 is added to the number $(ab)$ , then the result is $(ba)$ .

So $(ab)$ has value $10a+b$ and

$(ba)$ has value $10b+a$ .

We are given then:

$(ab)+18=(ba)$

$10a+b+18=10b+a$

Subtract $10a$ on both sides:

$b+18=10b+a-10a$

Simplify:

$b+18=10b-9a$

Subtract $b$ on both sides:

$18=10b-b-9a$

$18=9b-9a$

Divide both sides by 9:

$2=b-a$

Rearrange by commutative property:

$2=-a+b$

So the system of equations we want to solve is:

$a+b=10$

$-a+b=2$

-------------------------Add equations together (this will eliminate the variable $a$ and allow you to go ahead and solve for $b$ :

$0+2b=12$

$2b=12$

Divide both sides by 2:

$b=\frac{12}{2}$

Simplify:

$b=6$

If $b=6$ and $a+b=10$ , then $a=4$ . $a=4$ since 4+6=10.

So the original number is (46).

18 more than 46 is 18+46=(64) which is what we wanted.

We also have the sum of 4 and 6 is 10 as well.

7 0

3 years ago

The area of a square can be represented by the trinomial 9x^2 - 54x + 81. Which of the following is the length of one side of th

Mnenie [13.5K]

$Use\ (a-b)^2=a^2-2ab+b^2\\\\9x^2-54x+81=\underbrace{(3x)^2-2(3x)(9)+9^2}_{(*)}=(3x+9)^2\\\\\text{The formula of an area of a square with a side x:}\ A=x^2.\\\\\text{Therefore we have answer:}\ The\ length\ of\ side\ of\ the\ square\ is\ 3x+9.$

3 0

3 years ago

a flag pole that is 8 feet tall casts a shadow that is 6 ft long a nearby tree casts a shadow that is 21 ft long. How tall is th

Andru [333]

Answer:

The tree is 28 feet tall.

Step-by-step explanation:

It is given that:

Height of flag pole = 8 feet

Shadow of flag pole = 6 feet

Ratio of height to shadow = 8 : 6

Shadow of nearby tree = 21 feet

Height of nearby tree = x

Ratio of height to shadow = x : 21

8 : 6 :: x : 21

Product of means = Product of extremes

6x = 8*21

6x = 168

Dividing both sides by 6

$\frac{6x}{6}=\frac{168}{6}\\x=28$

Therefore,

The tree is 28 feet tall.

7 0

3 years ago