a grocery bag containing 4 potatoes weighs 2 pounds. An identical bag contains 12 potatoes weighs 4 pounds. Write an equation in standard form that shows the relationship of the weight (y) and the number of potatoes (x).
Use the ordered pairs to first find the slope then substitution into y=mx+b to find b
Let, the equation which represents relationship of the weight (y) and the number of potatoes (x) be
y=mx+c
y=2 when x=4
i.e. 4m+c=2 -------(1)
and y=4 when x=12
i.e. 12m+c=4 --------(2)
Subtracting equation (1) from (2), we get
8m=2
i.e. m=1/4
Putting value of m in (1), we get
1+c=2
i.e. c=1
So, an equation in standard form that shows the relationship of the weight (y) and the number of potatoes (x) is:
y= \(\dfrac{1}{4}x+1\)