Question

Can you tell me how to do it? Don't give me answers...I want to know how to solve it...
What is the value of x in the proportion (x-1)/5 = (4x + 2)/35?

Answer 1

\[\frac{ (x-1) }{5}=\frac{ 4x+2 }{ 35 }\]

Answer 2

cross multiply the top up

Answer 3

What do you mean?

Answer 4

\(\bf \cfrac{x-1}{5}=\cfrac{4x+2}{35}\quad \textit{times 35 each side}\\ \quad \\
{\color{red}{ \cancel{35}}}\cdot \cfrac{x-1}{\cancel{5}}={\color{red}{ \cancel{35}}}\cdot \cfrac{4x+2}{\cancel{35}}

\implies {\color{red}{ 7}}\cdot (x-1)={\color{red}{ 1}}\cdot 4x+2\\ \quad \\\implies 7x-7=4x+2\)

Answer 5

Ok i see but where did you get 7?

Answer 6

7(x-1) <--- distribution

Answer 7

hmm you meant the .... I see the 7 itself... hm ok

Answer 8

ok i get it! so next 3x = 9? then you divided by 3 and i got 3.

Answer 9

so the answer is 3?

Answer 10

\(\bf \cfrac{x-1}{5}=\cfrac{4x+2}{35}\quad \textit{times 35 each side}\\ \quad \\
{\color{red}{ 35}}\cdot \cfrac{x-1}{5}={\color{red}{ 35}}\cdot \cfrac{4x+2}{35}\implies

\cancel{\cfrac{{\color{red}{ 35}}}{5}}(x-1)=\cancel{\cfrac{{\color{red}{ 35}}}{35}}(4x+2)\)

Answer 11

yeah i got that :)

Answer 12

"so the answer is 3?" \(\checkmark\)

Answer 13

Thanks! i understand now! can you help me another question? and i'll try solve it and you check it?

Answer 14

ok

Answer 15

What is the value of x in the proportion x+1/x+3 = 15/21?

Answer 16

\[\frac{ x+1 }{ x+3 }=\frac{ 15 }{ 21 }\]

Answer 17

Is it same as you solve it? or different?

Answer 18

is that correct so far?