A. Corresponding parts of congruent triangles are congruent.
27y^3 -343 starts out with 27y^3, and 343 is the cube of 7. Thus, we know immediately that 27y3 -343 is the diffeence of two squares.
The appropriate rule is a^3 - b^3 = (a - b)(a^2 + ab + b^2).
Here, we have 27y3 -343 = (3y - 7)(9y^2 + 12y + 49)
Answer:
1) Isosceles
2) Scalene
3) Scalene
Step-by-step explanation:
The 1st choice is isosceles because 2 side lengths are equal.
The 2nd and 3rd choice are scalene because none of the sides equal the other sides.
Make x=0 in the second equation, giving you y=-3. If you plug that in to the top equation you would get x-3(-3)=-19, x+9=-19,x=-28.