On a piece of paper graph y< x+1

Justin is asked to solve the following system of linear equations using the elimination method.

romanna [79]

Alright, lets get started.

Justin is asked to solve the linear equations using elimination method.

By using elimination method means we have to multiply some numbers in our given equations in such a way that the co-efficient of x or y become same in both equations so that we could add or subtract them to cancel one of the term either x or y.

So, given equations are :

$5x - 12 = 3$

$-20x + 14 y = 13$

See we have 5x in first equation and -20x in second equation.

So, we try to change 5x into 20 x by multiplying it with 4, both of the equations will have 20 x in common

Lets multiply 4 in first equation

$4 * (5x-12y) = 4 * 3$

$20x - 48y = 12$

Now both equations could be added and 20 x will be cancelled out and we could easily find the value of y then solve for x.

So, Justin should try to change 5 so that it will be cancels, so option B : Answer

Hope it will help :)

3 0

2 years ago

I’ll make brainlest. help asap pls

Liono4ka [1.6K]

Answer:

(2, -1)

Step-by-step explanation:

We can add the first equation by the second

(4x + 6y = 2)+(-4x + 4y = -12)=

10y=-10

we divide both sides by 10 to get

y=-1

We plug -1 in the second equation to get:

-4x+4(-1)=-12

-4x-4=-12

-4x=-8

Now, we divide both sides by -4

x=2

Hope this helps!

6 0

2 years ago

Begin by clearly stating the problem; you can copy this from the problem set file. Show how you solved the problem step by step,

Y_Kistochka [10]

Answer: 13%

Step-by-step explanation:

The formula to find the simple interest is given by :-

$I=Prt$ , where P is the principal amount, r is rate of interest () in decimal and t is the time ( in years).

Given : P = $19,100 , I=$9932.00 and t= 4 years

Substitute all the above values in the formula , we get

$9932.00=(19100)r(4)\\\\\Rightarrow\ r=\dfrac{9932}{19100\times4}\\\\\Rightarrow r=\dfrac{13}{100}=0.13$

In percent , $r=0.13\times100=13\%$

Hence, the rate of interest = 13%

6 0

2 years ago

270 american dollars to 3000 pesos

yarga [219]

That is not a question. Did you mean $270 to pesos? Or 3000 pesos to Us

8 0

3 years ago

Read 2 more answers

You decide to enter in a rowing competition. To train, you go to the boat house and begin rolling down stream. You row for the s

fredd [130]

Answer:

Time spent rowing down stream $=100\ seconds$

Speed of boat in still water $=14\ ms^{-1}$

Step-by-step explanation:

Let speed of boat in still water be $= x\ ms^{-1}$

Speed of current $= 10\ ms^{-1}$

Speed of boat down stream = $\textrm{Speed of boat in still water +Speed of current}= (x+10)\ ms^{-1}$

Distance rowed down stream = 2400 m

Time spent rowing down stream = $\frac{Distance}{Speed}=\frac{2400}{x+10}\ s$ = $\frac{Distance}{Speed}=\frac{2400}{x+10}\ s$

Speed of boat up stream = $\textrm{Speed of boat in still water -Speed of current}= (x-10)\ ms^{-1}$

Distance rowed up stream = $\frac{1}{6} \textrm{ of distance rowed downstream}=\frac{1}{6}\times 2400 = 400\ m$

Time spent rowing up stream = $\frac{Distance}{Speed}=\frac{400}{x-10}\ s$

We know that,

$\textrm{Time spent rowing down stream =Time spent rowing up stream}$

So,

$\frac{2400}{x+10}=\frac{400}{x-10}$

Cross multiplying

$2400(x-10)=400(x+10)$

Dividing both sides by $400$

$\frac{2400(x-10)}{400}=\frac{400(x+10)}{400}$

$6(x-10)=x+10$

$6x-60=x+10$

Adding 60 to both sides.

$6x-60+60=x+10+60$

$6x=x+70$

Subtracting both sides by $x$

$6x-x=x+70-x$

$5x=70$

Dividing both sides by 5.

$\frac{5x}{5}=\frac{70}{5}$

∴ $x=14$

Speed of boat in still water $=14\ ms^-1$

Time spent rowing down stream = $\frac{2400}{14+10}=\frac{2400}{24}=100\ s$

3 0

2 years ago