Question

two numbers whose product is 64 and the sum is 8

Answer 1

\(\Huge\color{green}{ \rm a \times b =64 }\)
\(\Huge\color{green}{ \rm a + b =8 }\)

solve, doesn't matter which one is which.

Answer 2

NO

Answer 3

Look at what you wrote again.

Answer 4

So, you see what your mistake is ?

Answer 5

let 2 numbers be x and y
xy=64
sum = f(x) = x+y = x+64/x
now minimize f(x)

Answer 6

Yes,

Answer 7

Anyway, ...

\(\Huge\color{red}{ \it a + b =8 }\)
\(\Huge\color{red}{ \it a =8-b }\)

\(\Huge\color{red}{ \it (b-8) \times b =64 }\)
\(\Huge\color{red}{ \it b^{2}-8b =64 }\)
\(\Huge\color{red}{ \it b^{2}-8b +64=0 }\)

solve using the quadratic formula, ....

Answer 8

the last equation is \(\Huge\color{red}{ \it b^{2}-8b -64 =0 }\)