To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

3a - 5a = -2a

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

6a⁹ - 7a⁹ = -1a⁹

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 0. 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, -6) and (2, 6) so the slope becomes:

Plugging these values into the slope-intercept equation:

y = 3x + 0

To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y - 2)(y + 2)
(y x y) + (y x 2) + (-2 x y) + (-2 x 2)
y² + 2y - 2y - 4
y² - 4

The surface area of a cylinder is 2πr² + 2πrh:

sa = 2πr² + 2πrh
sa = 2π(1²) + 2π(1 x 1)
sa = 2π(1) + 2π(1)
sa = (2 x 1)π + (2 x 1)π
sa = 2π + 2π
sa = 4π