All categories

2 years ago

Solve: the quantity 3x minus 15 divided by 2 = 4x

Mathematics

1 answer:

Anon25 [30]2 years ago

5 0

Answer:

x=-3

Step-by-step explanation:

(3x-15)/2 = 4x

Multiply each side by 2

(3x-15)/2 *2= 4x*2

3x-15 = 8x

Subtract 3x from each side

3x-15-3x = 8x-3x

-15 = 5x

Divide each side by 5

-15/5 = 5x/5

-3 =x

You might be interested in

Fill in the table using this function rule. y=-4x+2 x y -1 0 1 2

Mariulka [41]

All you have to do is substitute all the Xs to and get a final y output.

for example:
if we take the number x is -1 all you do is:

y=-4(-1)+2
y=4+2
y=6
thats the first one done

7 0

2 years ago

A rectangular pool 18 meters by 12 meters is surrounded by a walkway of width x

vesna_86 [32]

Answer:

x=3 meters

Step-by-step explanation:

step 1

Find the area of the rectangular pool

$A=LW$

we have

$L=18\ m\\W=12\ m$

substitute

$A=18(12)=216\ m^2$

step 2

Find the area of rectangular pool including the area of the walkway

Let

x ----> the width of the walkway

we have

$L=(18+2x)\ m\\W=(12+2x)\ m$

substitute

$A=(18+2x)(12+2x)$

step 3

Find the area of the walkway

To find out the area of the walkway subtract the area of the pool from the area of rectangular pool including the area of the walkway

$A=(18+2x)(12+2x)-216$

step 4

Find the value of x if the area of the walkway equal the area of the pool

$(18+2x)(12+2x)-216=216$

Solve for x

$(18+2x)(12+2x)=432\\216+36x+24x+4x^{2}=432\\4x^{2} +60x-216=0$

Solve the quadratic equation by graphing

The solution is x=3 meters

see the attached figure

8 0

2 years ago

130 students choose to attend one of three after school activities: football, tennis or running. There are 58 boys. 49 students

cestrela7 [59]

Answer: $\dfrac{27}{65}$

Step-by-step explanation:

There are 130 students.

There are 58 boys --> 72 girls

A) 49 chose football: 27 are girls --> 22 are boys

B) 72 girls: 24 chose running, 27 chose football --> 21 girls chose tennis

C) 27 students chose tennis: 21 are girls --> 6 are boys.

D) 58 boys: 22 chose football, 6 chose tennis --> 30 boys chose running.

$\large\boxed{\begin{array}{l|cc||c}&\underline{Boys}&\underline{Girls}&\underline{Total}\\Football&22&27&49\\Tennis&6&21&27\\\underline{Running}&\underline{\quad 30\quad}&\underline{\quad 24\quad}&\underline{\quad 54\quad}\\Total&58&72&130\end{array}}$