contestada

Given the system of equations presented here:

3x + 5y = 29 x + 4y = 16

Which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated?

A) Multiply the second equation by −1 to get −x − 4y = −16
B) Multiply the second equation by −3 to get −3x − 12y = −48
C) Multiply the first equation by −1 to get −3x − 5y = −29
D) Multiply the first equation by −3 to get −9x − 15y = −87

Respuesta :

kudzordzifrancis

ANSWER

The correct answer is option B

EXPLANATION


The equations are

[tex]3x+5y=29---(1)[/tex]


and


[tex]x+4y=16---(2)[/tex]


When we multiply the second equation by [tex]-3[/tex], we obtain;


[tex]-3x-12y=-48---(3)[/tex]


When we combine this new equation with equation (1).


[tex]-7y=-19[/tex]


We can see that [tex]x[/tex] has been eliminated from the equation.


We can then, solve for  [tex]y[/tex] and then substitute the result in to any of the equations to find [tex]x[/tex].


Hence the correct answer is option B



alinakincsem

Answer:

B) Multiply the second equation by −3 to get −3x − 12y = −48

Step-by-step explanation:

We are given two equations:

[tex]3x+5y= 29[/tex] --- (i)

[tex]x+4y = 16[/tex] --- (ii)

If we multiply the second equation by -3, we get:

[tex]-3(x+4y) = 16[/tex]

[tex]-3x-12y=-48[/tex] --- (iii)

Combining equation (i) and (iii) to get:

[tex]3x+5y-3x-12y=29-48[/tex]

3x and -3x cancel each other so x is eliminated and we are left with:

[tex]-7y= -19[/tex]

Therefore, the correct answer option is B) Multiply the second equation by −3 to get −3x − 12y = −48.

Otras preguntas