Day 5: Quiz 5: Answers

Quiz 5 : Answers

Question 1: Solve for Y

  a.)The answer is 3y = 7x - 22 

       1.) Get Y alone by adding 3y to each side of the equal sign. 

                     7x - 3y = 22

                          +3y = 22+3y

                     7x = 22+3y

       2.)    Now subtract 22 from each side 

                     7x = 22+3y

                   -22   -22

                    7x - 22 = 3y

                         ^^

           Your done! y is now alone, 3y = 7x - 22

  b.) The answer is 4y=-12-5x

        1.) Get Y alone by saubtracting 5x from each side of the equal side 

                    5x+4y = -12

                        4y = -12 - 5x

         Thats your answer! 4y = -12-5x

c.) The answer is Y= 2x - 10
         1.) Get Y alone, once again.
         2.) 2x - y = 10
                  +y     +y
              2x = 10 + y

         3.) now subtract 10 from each side
              2x - 10 = y

        So the answer is Y = 2x - 10

Question 2: Find the slope of the line

a.) ( 7, -9) (10,-12)
          1.) Y2-Y1  rise
               X2-X1  run
          2.) -12 - 9 = -21
                     10-7 = 3      reduced this is -7
                                                                 1

    The slope is -7 over 1.

b.) (5,15) (5,10)
         1.) Y2-Y1
              X2-X1
         2.) 10 - 15 = -5
                  5 - 5 =  0
    

    The slope is -5 over 0.

Question 3: Find the Y intercept

a.) (8,1) (2,-3) 

        1.) First you need to find the slope. Which is -4

                                                                            -6

        2.)Then once you do that plug it into the Y=mx+b form. So this equation I will use the point (8,1) so 1=-4/-6(8) + b

        3.) once you do that, divide -4 by -6 and multiply it by 8 which is 5.33 repeating.
        4.) Now you subtract 5.33 from each side of the equation to get B alone.
        5.)  = -4.33 because 1 minus 5.33 is -4.33

 The answer is y=-4 - 4.33
                           -6

b.) (5,7) (1,9)
        1.) Find the slope. Which is   1
                                                   -2

        2.) Now that you have found the slope you need to put it in Y = mx+b form. I am going to use to points (1,9) . The equation will look like this 9=  1  (1) +b
                                                              -2
        3.)To be able to find b you need to divide 1 by -2 and multiply it by 1. Which is -.5 so the entire equation is 9=-.5+b .
        4.) Now you have to add .5 to both sides so you can get b alone. So your answer for b is 9.5.

The answer is y = 1/-2 +9.5