Mackenzie works as a salesperson at an electronics store and sells phones and phone accessories. Mackenzie earns a $10 commission for every phone she sells and a $4 commission for every accessory she sells. On a given day, Mackenzie made a total of $126 in commission and sold 7 more accessories than phones. Write a system of equations that could be used to determine the number of phones sold and the number of accessories sold. Define the variables that you use to write the system.

Let p= the number of phones sold

Let a= the number of accessories sold

Step-by-step explanation:

10p+4a=126

a=p+7

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions

1 number

if we use a graphing calculator, there is only one such number that satisfies the conclusion of the mean value theorem, that is, a number such that

where the right-hand side is the average rate of change of f on the interval [0.5,0.75], which is the slope of the secant line.

in the attached graph, the black line is the secant line which has its slope as the average rate of change of f on [0.5,0.75], while the orange line is the only tangent line to the graph of f in the interval that satisfies the mvt conclusion.