Answer:cubic polynomial
Step-by-step explanation:
When the biggest degree of your polynomial is 3,your polynomials name is cubic polynomial
1. The correct statement is the first one, which is: <span>Add the two equations, solve for y, and then substitute –1 for y to find x.
</span>
2. Therefore, you have the following system of equations:
<span>
4x+8y=20
-4x+2y= -30
3. When you a</span>dd the two equations, and clear the variable "y", you obtain:
10y=-10
y=-1
4. Now, you must substitute -1 for y (y=-1) to find x, as below:
4x+8y=20
4x+8(-1)=20
4x-8=20
4x=20+8
4x=28
x=28/4
x=7