This is useful so that you can come up with a quick answer rather then sit down with paper to solve the whole problem.
<h3>
#1</h3>
Given: f(x) = 3x² -5x + 4
To find f(-2), simply substitute x = -2 in function f(x).
f(-2) = 3(-2)² -5(-2) + 4
f(-2) = 12 + 10 + 4
f(-2) = 26
Answer: 26
<h3>#2</h3>
For an ordered pair (x, y) in a relation, the y element represents the range.
Answer: range
The standard form of a line:

We have the equation of a line in the slope-point form:
use distributive property
add 3 to both sides
multiply both sides by 2
subtract x from both sides
change the signs

Let x = number of 5 cent coins.
Then there are (x+2) 10 cent coins.
Let y = 20 cent coins.
Total coins: x+(x+2)+y = 30
2x+y=28
y = 28-2x (1)
Total value: 0.05x + 0.1(x+2) + 0.2y = 3.80
0.15x + 0.2y + 0.2 = 3.80
0.15x + 0.2y = 3.60 (2)
Substitute (1) into (2).
0.15x + 0.2(28-2x) = 3.60
-0.25x + 5.60 = 3.60
2.00 = 0.25x
8 = x
From (1), obtain y = 28 - 2(8) = 12
Answer: (x+2) = 8+2 = 10
Louise has 10 10-cent coins