You can use the discriminant rule, which is :
b^2 -4ac
“exactly one solution” means that it is equal to zero
so:
b^2 -4(4)(9)=0
b^2 -4(36)=0
b^2 -144=0
b^2=144
square root both sides
b=12 or -12
hope this helps !
3
10/100=x/30
Cross multiply
100x=300
Divide each side by 100
X=3
To determine the sum of the arithmetic series, simply remember that i is the pattern that you are going by which is 1,2,3.
The top value on the sigma sign tells you the final value that you must go to.
So use the equation to go from 1 to 18. So it would be 2(1) + 9 + 2(2) + 9 etc.
