The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

c² + 3c - 1 = c + 2
c² + 3c - 1 - 2 = c
c² + 3c - c - 3 = 0
c² + 2c - 3 = 0

Next, factor the quadratic equation:

c² + 2c - 3 = 0
(c - 1)(c + 3) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 1) or (c + 3) must equal zero:

If (c - 1) = 0, c must equal 1
If (c + 3) = 0, c must equal -3

So the solution is that c = 1 or -3

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 3 + 3 + 2 + 9
p = 17

When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

You need to find the value of a so solve the first equation in terms of y:

4a + y = 9
y = 9 - 4a

then substitute the result (9 - 4a) into the second equation:

8a - 9(9 - 4a) = -1
8a + (-9 x 9) + (-9 x -4a) = -1
8a - 81 + 36a = -1
8a + 36a = -1 + 81
44a = 80
a = \( \frac{80}{44} \)
a = 1\(\frac{9}{11}\)