The answer would be m^2+3m+2=0 because the first “part” of the equation (x^2-5) is equal to m; in the equation it’s squared so it can be replaced by m^2. next, 3m is the same as 3(x^2+5) which is what you have when you see 3x^2+15. finally, you have to bring the -2 over from the other side so you have positive 2. hope this helps!
I'm guessing S^20 is actually referring to the 20th partial sum

, with

in the arithmetic case, and

in the geometric case.
(a) Combining like terms, we have

and invoking the formula

we end up with

(b) Multiply

by 1.1, then subtract this from

:


It is: 27/8 = 3 with a remainder of 3
It it called an equation. Equation consist of number, symbols, and a equal sign.
To solve, first do -2 times t and -2 times 8. Your equation would look like this after: -2T+(-16)=12. Then add 16 to each side. -2T=28. Next, divide by -2. T=-14 is your answer.