Slove by using elimination
3x+7y=27
-3x+y=21

x = -5

y = 6

Step-by-step explanation:

3x + 7y = 27      (I)

-3x + y = 21        (II)

Add equation (I) & (II) and so x will be eliminated and we can find the value of y.

(I)      3x + 7y = 27    

(II)     -3x + y = 21        {add}

                8y = 48

                   y = 48/8

                   y = 6

Plugin y = 6 in equation (I)

3x +7*6 = 27

3x + 42 = 27

       3x = 27 - 42

       3x = -15

         x = -15/3

x = -5

5104.38 inches

step-by-step explanation:

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)