6.1 Add and subtract polynomials  (Page 3/12)

Find the sum: $\left(2x^2-3xy-2y^2\right)+\left(5x^2-3xy\right)$ .

Find the difference: $\left(a^2+b^2\right)-\left(a^2+5ab-6b^2\right)$ .

Find the difference: $\left(m^2+n^2\right)-\left(m^2-7mn-3n^2\right)$ .

Simplify: $\left(x^3-x^{2}y\right)-\left(x{y}^2+y^3\right)+\left(x^{2}y+x{y}^2\right)$ .

Simplify: $\left(p^3-p^{2}q\right)+\left(p{q}^2+q^3\right)-\left(p^{2}q+p{q}^2\right)$ .

Evaluate: $3x^2+2x-15$ when

1. ⓐ $x=3$
2. ⓑ $x=\mathrm{-5}$
3. ⓒ $x=0$

Evaluate: $5z^2-z-4$ when

1. ⓐ $z=\mathrm{-2}$
2. ⓑ $z=0$
3. ⓒ $z=2$

The polynomial $\mathrm{-16}{t}^2+250$ gives the height of a ball $t$ seconds after it is dropped from a 250-foot tall building. Find the height after $t=0$ seconds.

The polynomial $\mathrm{-16}{t}^2+250$ gives the height of a ball $t$ seconds after it is dropped from a 250-foot tall building. Find the height after $t=3$ seconds.

The polynomial $6x^2+15xy$ gives the cost, in dollars, of producing a rectangular container whose top and bottom are squares with side x feet and sides of height y feet. Find the cost of producing a box with $x=6$ feet and $y=4$ feet.

The polynomial $6x^2+15xy$ gives the cost, in dollars, of producing a rectangular container whose top and bottom are squares with side x feet and sides of height y feet. Find the cost of producing a box with $x=5$ feet and $y=8$ feet.