All categories

2 years ago

Can somebody help me/tell me how to do these?

Mathematics

1 answer:

andreyandreev [35.5K]2 years ago

7 0

Hi! I'll try to help

It gives you two equations, one for "x" and one for "y"

All you have to do is replace the variable "y" with its value in the second equation. Might be kind of confusing so let's do one.

y=4x

3x-y=1

Since we know that "y" is the same as 4x, you can rewrite the equation as

3x-4x=1

Next, all you have to do is combine like terms as solve "3x-4x" which is -x

Let's rewrite the equation, then:

-x=1

You can simplify it to

x=-1

by dividing both sides by negative one, in other words swapping the negative sign so that "x" is positive

You might be interested in

Find the area of the following figure

Yuri [45]

Answer:

Step-by-step explanation:

First side times hight or 3x4=12

12 is a whole square, but this is a triangle (Half of a square)

So we divide by 2 to find the area. 12/2=6

7 0

3 years ago

Read 2 more answers

A train leaves in Zurich at 22 40 and arrives in Vienna 07 32 the next day Work out the Time train takes

myrzilka [38]

Answer:

The train takes 8 hours and 52 minutes.

Step-by-step explanation:

Both Zurich and Vienna are in the same time zone, so there is no time to adjust the time zone.

Leaves: 22:40

Arrives: 7:32

From 23 to 7:32 there are (7 - 0) + (24 - 23) = 8 hours.

32 + (60 - 40) = 32 + 20 = 52 minutes.

The train takes 8 hours and 52 minutes.

7 0

3 years ago

A manufacturer wants to make open tin boxes from pieces of tin with dimensions 8 in. by 15 in. by cutting equal squares from the

Stells [14]

Answer:

$\frac{5}{3}$ in

Step-by-step explanation:

Let x be the side of square.

Length of box=8-2x

Width of box=15-2x

Height of box=x

Volume of box= $L\times B\times H$

Substitute the values then we get

Volume of box=V(x)= $(8-2x)(15-2x)x=(15x-2x^2)(8-2x)$

$V(x)=120x-30x^2-16x^2+4x^3$

$V(x)=4x^3-46x^2+120x$

Differentiate w.r.t x

$V'(x)=12x^2-92x+120$

$V'(x)=0$

$12x^2-92x+120=0$

$3x^2-23x+30=0$

$3x^2-18x-5x+30=0$

$3x(x-6)-5(x-6)=0$

$(x-6)(3x-5)=0$

$x-6=0\implies x=6$

$3x-5=0\implies x=\frac{5}{3}$

Again differentiate w.r.t x

$V''(x)=24x-92$

Substitute x=6

$V''(6)=24(6)-92=52>0$

Substitute x=5/3

$V''(5/3)=24(5/3)-92=-52$

Hence, the volume is maximum at x= $\frac{5}{3}$

Therefore, the side of the square , $x=\frac{5}{3}$ in cutout that gives the box the largest possible volume.

5 0

3 years ago

Please help me with this question

Tema [17]

............................

8 0

3 years ago

Find the measure of the indicated angle to the nearest degree

Y_Kistochka [10]

Answer:

32°

Step-by-step explanation:

use this formula :

Now you want to get the angle be x, so the opposite side is 28 and hypotenuse is 53. Putting in the formula we get:

Sin(x) = 28/53

Sin(x)= 0.5283018868

So to find x just do Sin^-1

x = Sin^-1 (0.5283018868)

you get 31.8907918, ok so we just want the nearest degree and if we do that we get 32˚

if you put them into your calculator you will get 32˚ as your answer

5 0

3 years ago