Solve the system of linear equations using the substitution method. 2y + x = -15 and x = 3y A. (-6, -3) B. (-7, -6) C. (-8, -6) D. (-9, -3)

Question

asked Sep 25, 2023 79.4k views

2 Answers

WisdomPill · Answer 1 · 2023-09-27T02:56:03+0000

${ \green{ \tt{option \: (d)}}}$

Explanation:

Given,

${ \tt{2y + x = - 15}} \: { \to} \: { \tt {eq}^(n) (1)}$

${ \tt{x = 3y}} \: { \to} \: { \tt{ {eq}^(n) (2)}}$

Substitute the value of eqⁿ (2) in (1) then,

${ \tt{2y}} \: + \: { \red{ \tt{3y}}} \: = - 15$

${ \tt{5y = - 15}}$

Divide both sides by 5 then,

${ \tt{ (5)/(5)y = - (15)/(5)}}$

${ \red{ \boxed{ \tt{y = - 3}}}}$

Substitute the value of y in eqⁿ (2)

${ \tt{x = 3y}}$

${ \tt{x = 3( - 3)}}$

${ \red{ \boxed{ \tt{x = - 9}}}}$

Therefore, the value of (x,y) is (-9,-3)

Hence, option (d) is correct.