Math question! helllpppp? ?

Question

the values of the expression are 50, 45, 40, 35, 30 when x= 2,3,4,5,6

what is the expression?

Answer 1

Slope of a line is y=m*x +b

ANS:  y= -5*x + 60

The problem gives values of x and y.

X   Y

2  50

3  45

4  40

5  35

6  30

You can see that the relation is linear. This means that the equation has x only to the first power.

So the general equation of a line will be useful.

You can find the slope, then enter a point to find b.

(point slope method)

Slope m, is rise over run,  or the change in y  vs the change in x.   ( y2-y1)/x2-x1)

For the first two points,  the change in y is 50 to 45, so it is -5

and the change in x is 2 to 3  is 1.  (45-50)/(3-2)= -5

So the slope  m= -5

Now you have y= -5*x+b

Enter another set of points which are known solutions to the equation, and solve for b,

lets use points x=5 and y=35 into the equation.

35= -5*5 +b   solving for b

35+25=b

60=b   so now you know the relation  which produces the numbers is:

y= -5*x + 60

Check your work by entering another value, like x=6  and make sure y=30.

y= -5* 6 +60 = 30  so it is correct.

May the force be with you. . .

Answer 2

I can think of 60 - 5x

x=2

60-10=50

x=3

60-15=45

x=4

60-20=40

x=5

60-25=35

x=6

60-30=30

:D