Answer:
and 
Step-by-step explanation:
Given

Required
Find x and y
In the second equation. Assume that:

Substitute
in the first equation


Collect like terms


Multiply through by 5


Solve for x

Substitute this value of x in 





It would go along with, "if I get better grades, then I study."
The answer is 254.35 in square
1.

or if you mean (3x^3+5x^2+3x-7)+(8x-6x^2+6):

2.

Answer:
267.1115
Step-by-step explanation: