Write the word or phrase that best completes each statement or answers the question.
-$$x - 2 y = 1$$
$- 7 x - 3 y = - 75$
A) $( 8,5 )$
B) $( 9,4 )$
C) $( - 9,5 )$
D) Inconsistent, $\varnothing$

Question

Quizplus · Accepted Answer

One way to solve this system of equations is by using the substitution method. Solve the first equation for x:

$$x - 2y = 1$$
$$x = 2y + 1$$

Then substitute that expression for x in the second equation:

$$-7(2y+1) - 3y = -75$$
$$-14y - 7 - 3y = -75$$
$$-17y = -68$$
$$y = 4$$

Now substitute that value for y back into either of the original equations to solve for x:

$$x - 2(4) = 1$$
$$x = 9$$

So the solution to the system is (9,4), or choice B.

Write the Word or Phrase That Best Completes Each Statement x−2y=1x - 2 y = 1x−2y=1

Write the Word or Phrase That Best Completes Each Statement $x - 2 y = 1$