The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 1 x 9) + (2 x 9 x 2) + (2 x 1 x 2)
sa = (18) + (36) + (4)
sa = 58

You need to find the value of c so solve the first equation in terms of z:

-8c + z = -9
z = -9 + 8c

then substitute the result (-9 - -8c) into the second equation:

4c + 2(-9 + 8c) = -7
4c + (2 x -9) + (2 x 8c) = -7
4c - 18 + 16c = -7
4c + 16c = -7 + 18
20c = 11
c = \( \frac{11}{20} \)
c = \(\frac{11}{20}\)

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 -36 as well and sum (Inside, Outside) to equal -5. For this problem, those two numbers are -9 and 4. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 5y - 36
y² + (-9 + 4)y + (-9 x 4)
(y - 9)(y + 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, 1) and (2, 3) so the slope becomes:

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) + (8a²)(6b)
(9 x 5)(a x a x b) + (8 x 6)(a² x b)
(45)(a¹⁺¹ x b) + (48)(a²b)
45a²b + 48a²b
93a²b