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

-6b + z = -4
z = -4 + 6b

then substitute the result (-4 - -6b) into the second equation:

-3b - 2(-4 + 6b) = -5
-3b + (-2 x -4) + (-2 x 6b) = -5
-3b + 8 - 12b = -5
-3b - 12b = -5 - 8
-15b = -13
b = \( \frac{-13}{-15} \)
b = \(\frac{13}{15}\)

The volume of a cube is height x length x width:

v = h x l x w
v = 7 x 3 x 8
v = 168

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.

-5a - 6 > -3 - 9a
-5a > -3 - 9a + 6
-5a + 9a > -3 + 6
4a > 3
a > \( \frac{3}{4} \)
a > \(\frac{3}{4}\)

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.

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.

(4a)(2ab) - (4a²)(5b)
(4 x 2)(a x a x b) - (4 x 5)(a² x b)
(8)(a¹⁺¹ x b) - (20)(a²b)
8a²b - 20a²b
-12a²b