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.)

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.

-7x + 9 < 2 - 3x
-7x < 2 - 3x - 9
-7x + 3x < 2 - 9
-4x < -7
x < \( \frac{-7}{-4} \)
x < 1\(\frac{3}{4}\)

To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -6 as well and sum (Inside, Outside) to equal 5. For this problem, those two numbers are -1 and 6. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² + 5y - 6
y² + (-1 + 6)y + (-1 x 6)
(y - 1)(y + 6)

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

An acute angle measures less than 90°, a right angle measures 90°, and an obtuse angle measures more than 90°.