4.) 5x+4y=-30 3x –9y=-18 What is the solution to this problem

asked Mar 16, 2021 7.8k views

1 vote

4.)
5x+4y=-30
3x –9y=-18
What is the solution to this problem

8.3k points

Please log in or register to add a comment.

3 votes

$5x + 4y = - 30 | * ( - 3) \\ 3x - 9y = - 18 | * 5 \\ \\ - 15x - 12y = 90 \\ 15x - 45y = - 90$

Now add 2 equations

$- 57y = 0 \\ y = 0$

Now we need to put y into any equation

$- 15x - 12 * 0 = 90 \\ - 15x = 90 \\ x = - 6$

Answer: (-6;0)

Mcnesium answered Mar 22, 2021

8.7k points

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.2m questions

11.9m answers