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 equal sign and the answer on the other.

-y - 5 = 7 + 7y
-y = 7 + 7y + 5
-y - 7y = 7 + 5
-8y = 12
y = \( \frac{12}{-8} \)
y = -1\(\frac{1}{2}\)

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.

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° - 39° - 49° = 92°

So, d° = 49° + 92° = 141°

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° - 39° = 141°

A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.

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.

(9a)(5ab) - (9a²)(8b)
(9 x 5)(a x a x b) - (9 x 8)(a² x b)
(45)(a¹⁺¹ x b) - (72)(a²b)
45a²b - 72a²b
-27a²b