Answer:
1. y=18
2. x=5
3. y=2
Explanation:
y=2x
1.
As you have x, substitute (replace) x for 9 to find y.
2×9=18 (We times 2 by 9 because, in algebra, when a number is next to a letter, it means to times).
So, y=18
2.
As we know that y=10, do the same thing and substitute.
10=2x
Isolate x by dividing:
10÷2=5
So, x=5
3.
Substitute x:
2×1=2
So, y=2
Hope this helps :)