I've asked this before but I haven't gotten an answer how I need it :( I need to use the deffinition of the derivative to solve

Answer:

Step-by-step explanation:

hope this helps!

How to Solve using Algebra<span>Make both equations into "y =" format.Set them equal to each other.Simplify into "= 0" format (like a standard Quadratic Equation)Solve the Quadratic Equation!<span>Use the linear equation to calculate matching "y" values, so we get (x,y) points as answers</span></span>

Answer:

Plan A lasts for 1.5 hours

Plan B lasts for 0.5 hours

Step-by-step explanation:

Lena the trainer has two solo workout plans that she offers her clients: Plan A and Plan B

Let x the number of hours that plan A lasts( the time a client takes to complete workout)

Let y = the number of hours that plan B lasts. ( the time a client takes to complete workout)

On Wednesday, there were 12 clients who did Plan A and 2 clients who did Plan B.

This means 12 clients trained for 12x hours under plan A and 2 clients trained for 2y hours under plan B.

On Thursday, there were 3 clients who did Plan A and 5 clients who did Plan B.

This means 3 clients trained for 3x hours under plan A and 5 clients trained for 5y hours under plan B.

Lena trained her Wednesday clients for a total of 19 hours and her Thursday clients for a total of 7 hours.

This means

12x + 2y = 19 - - - - - - - - - - -1

3x + 5y = 7 - - - - - - - - - - -2

Using elimination method,

Multiply equation 1 by 3 and equation 2 by 12

36x + 6y = 57

36x +60y = 84

Subtracting,

54y = 27

y = 27/54 = 0.5 hours per client

Put y = 0.5 in 3x + 5y = 7

3x +5×0.5 = 7

3x + 2.5 = 7

3x = 7-2.5 = 4.5

x = 4.5/3 = 1.5 hours per client

Answer:

x=29

Step-by-step explanation:

2x+1+33=90

56=2x

x=29

Answer:

-8.45

Step-by-step explanation:

Look at -10 and 0 on the number line. I used a ruler to help me, and found that A and B were about 1 - 1.3 cm apart. I looked at the options and found that -8.45 was the closest.

However, another way you could of worked this out would be to look at your options and eliminate the ones you know don’t work. Then look at your options available and work it out from there.