Greetings!
Answer:
y = [tex]\frac{-18}{7}[/tex] and x = [tex]\frac{50}{7}[/tex]
Step-by-step explanation:
To solve simultaneous equations, you need to have the number in front of both x's or y's the same. (signs doesn't matter)
To get -x to -10x we simply need to multiply the first equation by 10:
-x * 10 = -10x
-9y * 10 = -90y
16 * 10 = 160
-10x - 90y = 160
Now we can add the two equations:
-10x + 10x = 0
-90y + 20y = -70y
160 + 20 = 180
-70y = 180
70y = -180
7y = -18
y = [tex]\frac{-18}{7}[/tex]
Now plug [tex]\frac{-18}{7}[/tex] into the second equation:
10x + 20([tex]\frac{-18}{7}[/tex]) = 20
10x - [tex]\frac{360}{7}[/tex] = 20
Move the [tex]\frac{360}{7}[/tex] over to the other side, making it a positive:
10x = 20 + [tex]\frac{360}{7}[/tex]
10x = [tex]\frac{500}{7}[/tex]
Divide both sides by 10:
x = [tex]\frac{50}{7}[/tex]
So y = [tex]\frac{-18}{7}[/tex] and x = [tex]\frac{50}{7}[/tex]
Hope this helps!
