Identify the factors of the function
y = 4x2 + 2x - 12

y = 2(x + 2)(2x - 3)

Step-by-step explanation:

Given

y = 4x² + 2x - 12 ← factor out 2 from each term

  = 2(2x² + x - 6) ← factor the quadratic

Consider the factors of the product of the x² term and the constant which sum to give the coefficient of the x- term.

product = 2 × - 6 = - 12 and sum = + 1

The factors are + 4 and - 3

Use these factors to split the x- term

2x² + 4x - 3x - 6 ( factor the first/second and third/fourth terms )

= 2x(x + 2) - 3(x + 2) ← factor out (x + 2) from each term

= (x + 2)(2x - 3)

Thus

2x² + x - 6 = (x + 2)(2x - 3) , and

y = 4x² + 2x - 12 = 2(x + 2)(2x - 3)  ← in factored form

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

b. f(x) = –√x + 3this is the correct answer