Question

​ y=−8x−3 x+y=7 ​ Is (3,4)(3,4)left parenthesis, 3, comma, 4, right parenthesis a solution of the system? Choose 1 answer: Choose 1 answer: (Choice A) A Yes (Choice B) B No

Answer 1

Given:

The system of equation is

$y=-8x-3$

$x+y=7$

To find:

Whether (3,4) is a solution of the given system or not.

Solution:

We have,

$y=-8x-3$          ...(i)

$x+y=7$            ...(ii)

Putting the value of y in (ii) from (i), we get

$x+(-8x-3)=7$

$x-8x-3=7$

$-7x=7+3$

$-7x=10$

Divide both sides by -7.

$x=\dfrac{10}{-7}$

$x=-\dfrac{10}{7}$

Putting $x=-\dfrac{10}{7}$ in (i), we get

$y=-8\times (\dfrac{-10}{7})-3$

$y=\dfrac{80}{7}-3$

$y=\dfrac{80-21}{7}$

$y=\dfrac{59}{7}$

So, the only solution of the given system is $\left(-\dfrac{10}{7},\dfrac{59}{7}\right)$.

Hence, (3,4) cannot be a solution of given system, Hence the correct option is B.

Answer 2

Answer: B I got it right in khan academy

Step-by-step explanation: