To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:

9z⁴ + 4z⁴
(9 + 4)z⁴
13z⁴

The distributive property for multiplication helps in solving expressions like a(b + c). It specifies that the result of multiplying one number by the sum or difference of two numbers can be obtained by multiplying each number individually and then totaling the results: a(b + c) = ab + ac. For example, 4(10-5) = (4 x 10) - (4 x 5) = 40 - 20 = 20.

To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.

First, solve for \( \left|z - 3\right| \):

\( \left|z - 3\right| \) - 2 = -2
\( \left|z - 3\right| \) = -2 + 2
\( \left|z - 3\right| \) = 0

The value inside the absolute value brackets can be either positive or negative so (z - 3) must equal + 0 or -0 for \( \left|z - 3\right| \) to equal 0:

So, z = 3 or z = 3.

By buying two shirts, Ezra will save $28 x \( \frac{10}{100} \) = \( \frac{$28 x 10}{100} \) = \( \frac{$280}{100} \) = $2.80 on the second shirt.