Question

multiply and simplify: $(x + 1)(4x + 5)$

Explanation:

Step1: Use FOIL method

$(x + 1)(4x+5)=x\times4x+x\times5 + 1\times4x+1\times5$

Step2: Calculate each product

$x\times4x = 4x^{2}$, $x\times5=5x$, $1\times4x = 4x$, $1\times5 = 5$

Step3: Combine like - terms

$4x^{2}+5x + 4x+5=4x^{2}+(5x + 4x)+5=4x^{2}+9x + 5$

Answer:

$4x^{2}+9x + 5$