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3 years ago

What is the answer to this problem

Mathematics

2 answers:

Alisiya [41]3 years ago

8 0

B, -3x+15=23 is the answer

IRINA_888 [86]3 years ago

7 0

The answer is B.
How?
Take the original equation and multiply the parenthesis by 3:
3x+15-6x=23
Now, unite the two x terms like this
3x-6x+15=23
Now, combine them by doing 3-6 (which is -3), and making that the coefficient on x:
-3x+15=23

You might be interested in

Lena [83]

Answer:

7.5kg

Step-by-step explanation:

Given that:

Monday:

Mass of sand = 24 kg

Mass of cement = 5 kg

Tuesday :

Mass of sand = 36 kg

Let mass of cement = c

Mass of cement required to make the same type of mortar mix

Mass of Sand = mass of cement

24kg = 5kg

36kg = c

By cross multiplication :

24 * c = 5 * 36

24c = 180

Divide both sides by 24

c = 180 / 24

c = 7.5 kg

Hence mass of cement required is 7.5 kg

4 0

3 years ago

The ratio of dogs to cats being treated at a veterinarian's office this week is 5 : 2. Suppose there are 168 dogs and cats sched

Alexeev081 [22]

Answer:

48 cats

Step-by-step explanation:

Am interesting factoid about ratios:

The ratio $a:b$ can be separated into fractional parts of $\frac{a}{a + b}$ and $\frac{b}{a + b}$ . We need to know the cat part. $\frac{2}{5 + 2} = \frac{2}{7}$ , so that is the fraction part. Then, we multiply this fraction by 168 to get the total number of cats. This number is 48.

4 0

3 years ago

Can someone help me with this?

Anna35 [415]

Answer:

Let 'a' be the first term, 'r' be the common ratio and 'n' be the number of terms

Series = 2+6+18.......= 2+2•3¹+ 2•3².......= 728

Now,

$Sum = \frac{a( {r}^{n} - 1) }{(r - 1)} \\$

So,

$\frac{a( {r}^{n} - 1)}{(r - 1)} = 728 \\ \frac{2( {3}^{n} - 1) }{(3 - 1)} = 728 \\ \frac{2( {3}^{n} - 1) }{2} = 728 \\ {3}^{n} - 1 = 728 \\ {3}^{n}=728+1\\ {3}^{n} = 729 \\ {3}^{n} = {3}^{6} \\ \boxed{ n = 6}$

Therefore, number of terms is 6

6 is the right answer.

3 0

3 years ago

Mark can remember only the first 4 digits of his friend's phone number. He also knows that the number has 7 digits and that the

denis-greek [22]

Answer:

19800 seconds, or 330 minutes, or 5 hours + 30 minutes

Step-by-step explanation:

Number Permutations

We know the phone number has 7 digits, 4 of which are known by Mark. This leaves him 3 digits to guess with. We also know the last one is not zero. The number can be represented as

XXY

Where X can be any digit from 0 to 9 and Y can be any digit from 1 to 9. The first two can be combined in 10x10 ways, and the last one can be of 9 ways, this gives us 10x10x9 = 900 possible permutations.

If each possible number takes him 22 seconds, every possibility will need

22x900=19800 seconds, or 330 minutes, or 5 hours + 30 minutes

3 0

3 years ago

Find the coordinate that divides the directed line segment from A(-2,-4) to B(8,1) in the ratio of 2 to 3

zalisa [80]

We have that
A(-2,-4) B(8,1) 

let
M-------> the coordinate that divides the directed line segment from A to B in the ratio of 2 to 3

we know that

A--------------M----------------------B
2 3
distance AM is equal to (2/5) AB
distance MB is equal to (3/5) AB
so

step 1
find the x coordinate of point M
Mx=Ax+(2/5)*dABx
where
Mx is the x coordinate of point M
Ax is the x coordinate of point A
dABx is the distance AB in the x coordinate
Ax=-2
dABx=(8+2)=10
Mx=-2+(2/5)*10-----> Mx=2

step 2
find the y coordinate of point M
My=Ay+(2/5)*dABy
where
My is the y coordinate of point M
Ay is the y coordinate of point A
dABy is the distance AB in the y coordinate
Ay=-4
dABy=(1+4)=5
Mx=-4+(2/5)*5-----> My=-2

the coordinates of point M is (2,-2)

see the attached figure

7 0

3 years ago