Question

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05:

xz(x² + y²)

Answer 1

 To find the product, we will use distributive law as follows: 

\[xz\left( x^2 + y^2 \right)\]

\[ = xz \times x^2 + xz \times y^2 \]

\[ = x^3 z + x y^2 z\]

Substituting x =  \[-\] 1, y = 0.25​ and z = 0.05​ in the result, we get:​

\[x^3 z + x y^2 z\]

\[ = \left( - 1 \right)^3 \left( 0 . 05 \right) + \left( - 1 \right) \left( 0 . 25 \right)^2 \left( 0 . 05 \right)\]

\[ = \left( - 1 \right)\left( 0 . 05 \right) + \left( - 1 \right)\left( 0 . 0625 \right)\left( 0 . 05 \right)\]

\[ = - 0 . 05 - 0 . 003125\]

\[ = - 0 . 053125\]