<h2>
Greetings!</h2>
Answer:
y =
and x = 
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 = 
Now plug
into the second equation:
10x + 20(
) = 20
10x -
= 20
Move the
over to the other side, making it a positive:
10x = 20 + 
10x = 
Divide both sides by 10:
x = 
So y =
and x = 
<h2>Hope this helps!</h2>
Answer:
Equation : y = 4x + 55.50
x = 1.9 gigabytes
Step-by-step explanation:
Given that:
Flat fee per month = $55.50
Cost per gigabyte = $4
Let,
x be the number of gigabytes.
y be the total cost
y = 4x + 55.50
Lily wants to keep her bill $63.10
63.10 = 4x + 55.50
63.10 - 55.50 = 4x
4x = 7.60
Dividing both sides by 4

Hence,
Equation : y = 4x + 55.50
x = 1.9 gigabytes