**Review and summary of the homework**

1. The
*solve*
command:

Without evaluating the following code, try to predict exactly what the output will be:

`> `
**solve( x^2 - x - 2 = 0, x );
solve( {a+b = 3, a-b = 1}, {a,b} );**

Now evaluate the expressions the check your predictions.

**Exercise**
: Use the
*solve*
command to find a pair of numbers whose sum is 10 and whose product is 21. Try it now.

`> `
**solve( {c+d=10, c*d=21});**

2. The
*plot*
command:

Plot the polynomial
for
=
to 4.

Does this range show all the roots to this polynomial?

Title your plot "Cubic Polynomial."

`> `
**plot(x^3-16*x^2+7, x=-4..4,title="Cubic Polynomial");**

**Polynomial with a power of three should have three roots shown.**