Answer:
6. Since, by given graph,
The end behavior of the function f(x),


Thus, the function f(x) must has odd number of roots ( where the graph of a function intersects the x-axis )
⇒ The function must has odd number of solutions,
Again by the graph,
Graph of the function intersects the x-axis 5 times ( it touches the origin so it have the repeated root of x = 0 ),
Hence, the total number of real solution of f(x) is 5.
7. Let x represents the width of the rectangle( in inches ),
Given,
The length is 10 inches longer than the width,
⇒ Length of the rectangle = ( x + 10 ) inches
Thus, the area of the rectangle,
A = length × width = x(x+10)
According to the question,
A = 144 in²
⇒ x(x+ 10) = 144


( Middle term splitting )


⇒ x = -18 or x = 8 ( By zero test property )
The width can not be negative,
Hence, the width of the rectangle would be 8 inches.