Y = 7x + 50. Use slope-intercept form (y = mx + b), where m is slope, and b is the y-intercept. Insert the values we already know into the equation. y = 7x + b. Now, insert the x and y-values of your order pair into the equation and solve for b. 8 = 7(-6) + b ---> 8 = -42 + b --> 8 + 42 = -42 + b + 42 --> 50 = b or b = 50. Now that we have the value of b, insert it into the equation as well, and then you have your answer. Answer: y = 7x + 50
Let x be your first alloy 2/5x+7/10(30-x)=1/2(30) 4x+210-7x=150 3x=60 x=20 So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
