1. all whole numbers
2.
Below are all possible outcomes:
2, 2 4, 2 7, 2 9, 2
2, 4 4, 4 7, 4 9, 4
2, 7 4, 7 7, 7 9, 7
2, 9 4, 9 7, 9 9, 9
The ones colored blue are the ones which have a product less than 30 and contain at least one odd number.
There are 6 of them.
3.
y = x + 6
y = x2 + 8x + 16 Substitute x + 6 in for y in this equation.
x + 6 = x2 + 8x + 16
Subtract x and subtract 6 from both sides.
0 = x2 + 7x + 10
Factor the right side.
0 = (x + 2)(x + 5)
Set each factor equal to zero and solve for x .
x + 2 = 0 or x + 5 = 0
x = -2 or x = -5
When x = -2 , y = x + 6 = -2 + 6 = 4 So (-2, 4) is a solution.
When x = -5 , y = x + 6 = -5 + 6 = 1 So (-5, 1) is a solution.