Exercise 3

In each of the equations below, find y when x is the given number:  $y = x^3+3x+2, x=-2$

In each of the equations below, find y when x is the given number:  $y = (x+1)(x+2), x=-1$

In each of the equations below, find y when x is the given number:  $y = (x+1)(x+2), x=-2$

In the equation $y =x^2+4x+4$, take different numbers, positive and negative, as $x$ and calculate $y$ . Why is y positive or zero in all cases?

Natural numbers, their negatives and zero are together called integers. How many pairs of integers are there, satisfying the equation, $x^2+y^2=25$?

Natural numbers, their negatives, and zero can be together called integers. How many pairs of integers $(x,y)$ can you find satisfying the equation $x^2-y^2=25$.

$1 \times 2 \times 3 \times 4 \times 5 = 120, what is (-1) \times (-2) \times (-3) \times (-4) \times (-5) ?$

$What is (1 \times 2 \times 3 \times 4 \times 5) + \left[\right(-1) \times (-2) \times (-3) \times (-4) \times (-5\left)\right] ?$