Could you help me on number 9 on page 70 please? I kept getting a 4.312 answer
Sure. Here’s the problem:
The first thing you should do here is get rid of that infernal :
From there, you can subtract to eliminate the 9y terms:
2x – 9y = 12
– (5x – 9y = 18)
–3x = –6
x = 2
Now use x = 2 to find y:
5(2) – 9y = 18
10 – 9y = 18
–9y = 8
y = –8/9
The question asks for the sum of x and y, so add them up!