\[1)\ f(x) = 4x;\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{4(x + h) - 4x}{h}.\]
\[2)\ f(x) = x - 1;\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{(x + h - 1) - (x - 1)}{h}.\]
\[3)\ f(x) = 4x^{2};\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{4(x + h)^{2} - 4x^{2}}{h}.\]
\[4)\ f(x) = x^{2} + 2;\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{\left( (x + h)^{2} + 2 \right) - \left( x^{2} + 2 \right)}{h}.\]
\[5)\ f(x) = x^{3} - x^{2};\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{\left( (x + h)^{3} - (x + h)^{2} \right) - \left( x^{3} - x^{2} \right)}{h}.\]
\[6)\ f(x) = 2x^{3} + x;\]
\[\frac{f\left( x_{0} + h \right) - f\left( x_{0} \right)}{h} =\]
\[= \frac{\left( 2(x + h)^{3} + (x + h) \right) - \left( 2x^{3} + x \right)}{h}.\]