How do you solve x^2 - 10x + 21= 0 graphically?

2 Answers
Jun 12, 2017

The graph is given below

Explanation:

Here it is graph{(x^2)-(10x)+21 [-3.705, 16.295, -5.055, 4.945]}

Note that at x=5 you see it is the minimum

Jun 12, 2017

x=3" or " x=7

Explanation:

"from the graph of " x^2-10x+21
graph{x^2-10x+21 [-10, 10, -5, 5]}

"the solution to "

x^2-10x+21=0" are the values of x where the"
"graph crosses the x-axis"

rArrx=3" or " x=7

color(blue)"As a check"

"Substitute these values into " x^2-10x+21

x=3to9-30+21=0larrcolor(red)" True"

x=7to49-70+21=0larrcolor(red)"True"