Question

HELP will fan and medal

I need help understanding how I would write (and solve) the answer to this question:
Using complete sentences, write an indirect proof proving that if x = 30, then 3 over 4x + 5 ≠ 20.

Answer 1

Wait are you asking if 20 is the right answer?

Answer 2

x = 30 , the 3 / 4 x + 5 (insert not equal sign) 20

Answer 3

oh ok

Answer 4

so basically i just have to write how to solve it? or?

Answer 5

@MakaylaTracy @mathmath333 help please. if you're able

Answer 6

for indirect proof

lets assume that

\(\large\tt \begin{align} \color{black}{4x + 5 = 20
}\end{align}\)

then

\(\large\tt \begin{align} \color{black}{4x + 5 = 20\\~\\~\\
4x=20-5=15\\~\\~\\
\bf x=\dfrac{15}{4}\approx 3.7
}\end{align}\)

but this contradicts thr given data that

\(\large\tt \begin{align} \color{black}{\bf x=30
}\end{align}\)

hence
\(\Large\tt \begin{align} \color{black}{4x + 5 \neq 20.
}\end{align}\)

Answer 7

Ohh. okay. So because 4x+5= 30 the statement given was correct?

Answer 8

@mathmath333

Answer 9

okay wait. i just reviewed it again. so because it does not equal 30 the statement was correct

Answer 10

\(\large\tt \begin{align} \color{black}{4x+5\\
=4\times 30+5\\
=125\\



}\end{align}\)
so

\(\huge\tt \begin{align} \color{black}{4x+5=125



}\end{align}\)

Answer 11

Okay. Would I follow this same format for the equation 3/4x + 5 ≠ 20

Thank you so much by the way, this is all starting to make sense.

Answer 12

\[3/ 4x + 5 ≠ 20\] ***

Answer 13

@mathmath333

Answer 14

rewrite the full question

Answer 15

write an indirect proof proving that if x = 30 \[3/4x +5\neq20\]

^ full question

Answer 16

ok apply the same method as i stated before