I need help w/ Algebra homework (functions, probability)?

Question

here are a few problems that i am having issues with:

Find the coordinates of the x-intercept for y=3x-18.

Given f (x)= 2x^2-x+1, what is the value of f(-3)?

Given f (x)=2x+1 and g(x)=-4x, find the value of (f o g)(2).

Two cards are selected from a standard deck of 52 cards. What is the probability of getting a queen first and a 7 of hearts second?

thx!

Answer 1

To find the x-intercept for y = 3x -18, set y equal to zero and solve for x:

3x - 18 = 0

3x = 18

x = 6

Given f(x) = 2x^2 - x + 1, what is the value of f(-3)?

Just plug and chug!

Substitute (-3) for x in the equation:

f(-3) = 2(-3)^2 - (-3) + 1

f(-3) = 2(9) + 3 + 1

f(-3) = 18 + 4

f(-3) = 22

Two cards are selected from a standard deck of 52 cards.

What is the probability of getting a queen first and a 7 of hearts second?

Probability = 4/52 * 1/51 = 1/663 = 0.001508 or .151%

(about 1/6th of 1%)

Good luck in your studies,

~ Mitch ~