All categories

2 years ago

Can someone show me what i did wrong? x is supposed to equal 2

Mathematics

2 answers:

poizon [28]2 years ago

8 0

In step 3, you added 8x onto the other side instead of subtracting it from 15x.

Valentin [98]2 years ago

3 0

$\bf \begin{array}{rllll} 3(5x-4)&=&8x+2\\\\ 15x-12&=&8x+2\\\\ 7x-12&=&2&\leftarrow \textit{notice here}\\\\ 7x&=&14\\[1em] x&=&\cfrac{14}{7}\\[1em] x&=&2 \end{array}$

You might be interested in

Find the measure of the angle with the red dot (NOT X.)<br> Picture Included. Thank you!

Afina-wow [57]

Step-by-step explanation:

I can't see picture very well but as I see first angle is

-4x+5 and second is -13x+39 ( if it isn't, correct me)

sum of this angles is 180° because they are inner angles

(-4x+5) + (-13x+39) = 180

-4x+5 -13x+39=180

-17x+44=180

-17x = 180-44

-17x= 136

x= -8

angle -4x+5 will be:

-4*-8 + 5= 32+5= 37°

3 0

2 years ago

Mrs.cyan paid $105 for flower boxes. each flower box cost $7. how many flowers did she buy

Ede4ka [16]

Answer:

Step-by-step explanation:

To find how many she bought, we have to divide. So we do 105/7=15.

8 0

1 year ago

Read 2 more answers

Given LaTeX: f\left(x\right)=x^{^3}-3x+4f ( x ) = x 3 − 3 x + 4, determine the intervals where the function is increasing and wh

Vedmedyk [2.9K]

Answer:

Increasing: $x$ and $x>1$ .

Decreasing: $-1$

Step-by-step explanation:

We have been given a function $f(x)=x^3-3x+4$ . We are asked to determine the intervals, where the function is increasing and where it is decreasing.

First of all, we will find critical points of our given function by equating derivative of our given function to 0.

Let us find derivative of our given function.

$f'(x)=\frac{d}{dx}(x^3)-\frac{d}{dx}(3x)+\frac{d}{dx}(4)$

$f'(x)=3x^{3-1}-3+0$

$f'(x)=3x^{2}-3$

Let us equate derivative with 0 as find critical points as:

$0=3x^{2}-3$

$3x^{2}=3$

Divide both sides by 3:

$x^{2}=1$

Now we will take square-root of both sides as:

$\sqrt{x^{2}}=\pm\sqrt{1}$

$x=\pm 1$

$x=-1,1$

We know that these critical points will divide number line into three intervals. One from negative infinity to -1, 2nd -1 to 1 and 3rd 1 to positive infinity.

Now we will check one number from each interval. If derivative of the point is greater than 0, then function is increasing, if derivative of the point is less than 0, then function is decreasing.

We will check -2 from our 1st interval.

$f'(-2)=3(-2)^{2}-3=3(4)-3=12-3=9$