Solve for x.

7x+15=2x+19

a)x=9/34
b)x=4/9
c)x=4/5
d)x=20

7x+15=2x+19
Subtract 2x from both sides
5x+15=19
Subtract 15 from both sides
5x=4
Divide 5 on both sides
Final C.) x= 4/5

Let's solve your equation step-by-step.    7x+15=2x+19
Step 1: Subtract 2x from both sides.    7x+15−2x=2x+19−2x 
                                                                        5x+15=19

Step 2: Subtract 15 from both sides.    5x+15−15=19−155x=4
Step 3: Divide both sides by 5.                      5x/5=4/5
                                                                             x=4/5

Is there a picture of a graph or whatever that goes along with this?

Answer

1 number

explanation

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.