Question

Multiply the monomial by the binomial and find the value for x = −1, y = 0.25 and z = 0.05: −3x(y² + z²)

Answer 1

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

\[- 3x\left( y^2 + z^2 \right)\]

\[ = - 3x \times y^2 + \left( - 3x \right) \times z^2 \]

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

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

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

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

\[ = - 3\left( - 1 \right)\left( 0 . 0625 \right) - 3\left( - 1 \right)\left( 0 . 0025 \right)\]

\[ = 01875 + 0 . 0075\]

\[ = 0 . 195\]