A. you would put in 7 for X and 3 for Y.
3 + 7 = 10
2(10) = 20
In this problem, we need to plug in the given x values for

and find a and b.
When we plug in 1, we get:

Simplify:



We got our first statement about the values of the variables. If we find one more we can find those 2 variables.
We have another given root: 4.
Plug it in:




Now we have our second one. We can combine them:

I use elimination method which is easier here.
Multiply the top equation by -1:

Add them up:

Simplify:

Now we have a, we can plug in one of those equations to find b:



So, the answers are

and

.
Answer:459.27
Step-by-step explanation:
If I'm doing this correctly, you would need to multiply everything inside the parenthesis by 8. So it would be 8x-24y·8x+24y. I'm sorry if that's not right, but that is my interpretation of the problem. Hope I was of some assistance :)
To find 10per cent just divide by 10, the answer is 8