Answer:
y = 9x/5 + 50
Step-by-step explanation:
We are represent the information as coordinate (x,y)
If the cost for an order of 100 kilograms of steel bars is $230, this is expressed as (100, 230)
Also if the cost for an order of 150 kilograms of steel bars is $320, this is expressed as;
(150, 320)
Find the equation of a line passing through the points. The standard form of the equation is expressed as y = mx+c
m is the slope
c is the intercept
Get the slope;
m = y2-y1/x2-x1
m = 320-230/150-100
m = 90/50
m = 9/5
Get the y-intercept by substituting m = 9/5 and any point say (100, 230) into the expression y = mx+c
230 = 9/5(100)+c
230 = 9(20)+c
230 = 180 + c
c = 230-180
c = 50
Get the required equation
y = mx+c
y = 9/5 x + 50
Hence an equation for the cost of an order of steel bars (y) in terms of the weight of steel bars ordered (x) is y = 9x/5 + 50
