Two mechanics worked on a car. the first mechanic worked for 20 hours, and the second mechanic worked for 5 hours. together they charged a total of 2900. what was the rate charged per hour by each mechanic if the sum of the two rates was 235 per hour?

The rate per hour of the 1st mechanic is US$ 115, and the rate of the 2nd mechanic is US$ 120.

Step-by-step explanation:

1. Let's review all the information given to answer the question correctly.

Time of the 1st mechanic working on the car = 20 hours

Time of the 2nd mechanic working on the car = 5 hours

Total rate of the work done by the two mechanics = US$ 2,900

2. What was the rate charged per hour by each mechanic if the sum of the two rates was 235 per hour?

Rate per hour of the 1st mechanic = x

Rate per hour of the 1st mechanic = 235 - x

For solving the value of x, we will use the following equation:

x * 20 + 5 * (235 - x) = 2,900

20x + 1,175 - 5x = 2,900

15x = 2,900 - 1,175 (Like terms)

15x = 1,725

x = 115 (Dividing by 15 at both sides)

The rate per hour of the 1st mechanic is US$ 115, therefore the rate of the 2nd mechanic is US$ 120 (235 - 115).

Total charged by the 2 mechanics = 115 * 20 + 120 * 5

Total charged by the 2 mechanics = 2,300 + 600

Total charged by the 2 mechanics = 2,900

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

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x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this