Well first you substitute -3 for y and then subtract 12 from both sides of the equation and it should look like -15=-3x. Then divide 3 on both sides and you should end up getting 5=x.
45 90
/ \ / \
5 9 45 2
/ \ / \
3 3 5 9
5x3x3 / \
3 3
2x5x3x3
Add all the numbers of the triangle and then divide them by the sides
Answer:
5-12n is the answer
Step-by-step explanation:
-8n -4n =12ñ
