I need help with graph problems

Simplify this expression. 8x 16(x + y)

The function below is written in vertex form or intercept form. rewrite them in standard form and show your work. y = (x+4)(x+3)

The length of a rectangular plot of land is given by the expression 6x^3y^4. the width of the plot is given by the expression 5x^5y^4z. find an expression to represent the area of the rectangular plot.