Answer:
x = 4.69565 to the nearest tenth 4.7 hours after 9am the two stocks will be the same price.
Explanation:
The information gives the Slope and y intercept of the line for stock A. At 9am, time = 0, the stock price is $15.11, the y intercept or b. The Slope of the line is 12 cents per hour, it is a positive Slope so it will rise from left to right.
The line in Slope form is
y= 0.12x+15.11
Stock B at noon, so 3 hours later, is $15.86 and is decreasing at a rate of 11 cents per hour.
We know the Slope is -0.11 and we know a point on its line is (3,15.86). From this we can solve for the y intercept by substituting the x and y values from the coordinate into the Slope equation.
15.86 = -0.11(3) + b
15.86 = -0.33 + b
Add 0.33 to both sides
16.19 = b so the equation of the line of stock B is y= - 0.11x + 16.19
Since we have two equations solved for y, we can set them equal to each other and solve for x
0.12x + 15.11 = - 0.11x + 16.19 add 0.11x - 15.11 to both sides
0.23x = 1.08 divide both sides by 0.23 to solve