geno3141

One way is to arrange them like this:

 3x + 2y  =  6    --->      multiply this equation x 2           --->   6x + 4y  =  12

-6x - 3y  =  -6   --->      leave this one alone          ---------->  -6x - 3y  =  -6 

Now, if you add down the columns, the x-term will disappear:              y  =  6

Substituting y = 6 into the first equation:    

    3(6) + 2y  =  6      

       18 + 2y  =  6

               2y  =  -12

                 y  =  -2

The idea behind this method:  multiply an equation (or both equations) by a number (or by numbers) so that, when you add down, one of the variables will disappear.            

pi  =  3.1415926535898...

Your calculator rounded the value while the computer just stopped at that place without rounding.

2/3 ÷ 7/2                         When you are dividing by a fraction, multiply by its reciprocal:

2/3 x 2/7

4/21

Use a calculator and round the numer to the 4th digit behind the decimal point.

If the fifth digit is 5 or larger, increase the 4th digit by one;

If the fifth digit is 4 or smaller, leave the 4th digit as it is.

Equations are usually easier to solve if they do not have denominators.  The common denominator is 6, so multiply each term by 6:

  6(2x/3)  =  6(x/6) + 6(12)

          4x  =  x + 72

Get all the x-terms to one side; subtract x from both sides:

    4x - x  =  x - x + 72

          3x  =  72

Divide both sides by 3:

           x = 24

If you solve the formula for y, getting  y  =  mx + b, m will be the slope.

To solve  2y  =  6x - 4  for y, divide both sides by 2:

  y  =  3x - 4/3

The slope = 3; the y-intercept is -4/3

See the answer under your previous post.

If you have any questions on how to complete the instructions, post back.

See if you can use the instructions of question 1 to help you with question 2; if you need help, post back.

1 yard = 36 inches.

To find 1/4th of 36 inches, divide 36 by 4.

That number has been rounded to 3 decimal places; the answer is the given number.

Giving you some suggestions to solve the first problem:

If you have a calculator that has STAT capabilities, learn how to use the calculator; that will save you much time.

1)  Find the sum of all the frequencies; divide each frequency by this sum for each row.

2) Draw a histogram, using the values of X for the x-axis, the values found in step 1 for the y-axis.

3) How many golfers got a 7? How many golfers are there? Divide.

4) How many total golfers got a score no more than 6 (that is, 6 or less)? How many golfers are there. Divide.

5) What is the most likely score?

6) Use:  s = √[ ( ∑f·(x - mean)² ) / ( n - 1) ]

7) Find mean ± 2 standard deviations; which scores are above/below that point?

Try the above for problem #1.

To subtract comon fractions, they have to have a common denominator. Since the denominators are  3  and 15, and since  3  divides into  15  5  times, use  15  as the common denominator.

To change the fraction  7/3  multiply both the numerator and the denominator by  5,  giving you  35/15.

35/15 - 8/15  =  27/15   

Both the numerator and the denominator can be divided by 3, so a simpler answer is  9/5.