Question

The Johnson's are moving to another house. It's takes dad 5 hours to pack all the boxes and it takes 3 hours for mum to pack them. If mom and dad work together, how many hours will it take them to pack all the boxes?

Answer 1

i have a feeling its \[\frac{ 1 }{ 5 } + \frac{ 1 }{ 3 } = \frac{ 1 }{ x }\]

Answer 2

my year? If you mean class I'm in Alg 2

Answer 3

Yep that's correct

Answer 4

idk what to do now

Answer 5

@phi could you help me?

Answer 6

can you add the left side?

Answer 7

what do you mean? like = 1/8

Answer 8

No it's not 1/8

Answer 9

1/3 + 1/5 = 5/15 + 3/15 = 8/15

so 8/15 = 1/x

thus, x = 15/8

Answer 10

\[\frac13=\frac{1\times5}{3\times5}=\frac5{15}\]\[\frac15=\frac{1\times3}{3\times3}=\frac3{15}\]\[\frac13+\frac15=\frac5{15}+\frac3{15}=\frac8{15}\]

Answer 11

ohhhh u basically just multiplied 1/5 by 3/3 and 1/3 by 5/5 , do i just flip the 8/15 and divide next?

Answer 12

\[\frac1x=\frac8{15}\]\[\frac1{\frac1x}=\frac1{\frac8{15}}\]\[x=\frac{15}8\]

Answer 13

You can ignore the second step if you don't understand it.

Answer 14

ok :), would i just divide 15/8 and reduce the answer so I'd get 1.9 hours?

Answer 15

Yep

Answer 16

ok ty

Answer 17

no problem