SAT Math #4

A biologist develops the equation y = 20.942x + 127 to predict the regrowth of a certain species of plant x months after a natural disaster occurred. Which of the following describes the number 20.942 represents in this equation?

• The estimated number of the plants after x months

• The estimated monthly increase in the number of plants

• The estimated monthly decrease in the number of the plants

• The estimated number of the plants that survived the natural disaster

Which of the following expression is equivalent to 25x² - 4/9?

• √(5x - 2/3)

• x(5x - 2/3)

• (5x + 2/3)(5x - 2/3)

• (25x + 2/3)(25x - 2/3)

Which of the following could be the factored form of the equation graphed in the figure?

• y = (x - 1)(x+ 3)

• y = -(x - 1)(x + 3)

• y = (x + 1)(x - 3)

• y = -((x + 1)(x - 3)

Using the figure, if line Q (not shown) is the result of translating line left 4 units and down 3 units, than what is the slope of line Q?

• 1

• 4/3

• -4/3

• 3/4

Acceleration is the rate at which the velocity of an object changes with respect to time, or in other words, how much an object is speeding up or slows down. The average acceleration of an object can be found using the formula shown above, where t is the time over which acceleration is being measured, v_f is the final velocity, and v_i is the initial velocity.

a = (v_f - v_i)/ t

What of the following represents t in terms of the other variables?

• t = a / (v_f - v_i)

• t = (v_f - v_i) / a

• t = a(v_f - v_i)

• t = 1/a(v_f - v_i)

Which of the following equations could represent a parabola that has a minimum value of -5 and whose axis of symmetry is the line x = 1?

• y = (x - 5)² + 1

• y = (x + 5)² + 1

• y = (x - 1)² - 5

• y = (x + 1)² - 5

If (A, B) is the solution to the system of equations shown in the graph, what is the value of A + B?

• -2

• -6

• 2

• 6

If A = x² + 4x + 9 and B = x³ + 6x - 2, what is 3A + B.

• 4x² + 18x + 25

• x³ + x² + 10x + 7

• x³ +3x² + 18x + 25

• 3x³ + 3x² + 30x + 29

How many real values of x satisfy the quadratic equation

9x² - 12x + 4 = 0?

• 0

• 1

• 2

• 4

Which of the following represents the solution set for the inequality 3/5(x + 2/7) > -6

• x > -72/7

• x > -216/35

• x > -136/35

• x > -18/7