The formula for area is πr²:

a = πr²
a = π(3²)
a = 9π

An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 35° - 54° = 91°

So, d° = 54° + 91° = 145°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 35° = 145°

The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is -4. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -10) and (2, 2) so the slope becomes:

Plugging these values into the slope-intercept equation:

y = 3x - 4

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(2a)(8ab) - (7a²)(4b)
(2 x 8)(a x a x b) - (7 x 4)(a² x b)
(16)(a¹⁺¹ x b) - (28)(a²b)
16a²b - 28a²b
-12a²b

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.)