Please show your steps. Thanks!
2007-01-22 03:49:45 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Express in standard form
2007-01-22 03:59:18 · update #1
3i/(4+7i)=
3i(4-7i)/(4+7i)(4-7i) Multiplying and dividing by 4-7i (the conjugate)
= 3i(4-7i)/65
= (21 + 12i)/65
2007-01-22 03:55:04 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Multiply numerator and denominator by the conjugate of the denominator
3i/(4+7i) = 3i(4-7i)/(4+7i)(4-7i) = (12i -21i^2)/ (16-49i^2)=
(21+12i)/65 because i^2 = -1
=21/65 +(12/65)*i
2007-01-22 04:41:42 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋
In order to make the bottom a real number, multiply it by (4-7i). You have to do that to the top as well, of course
(3i)(4-7i)/ [(4+7i)(4-7i)]
(12i-21i²)/(16+49)
(21+12i)/65
2007-01-22 03:53:41 · answer #3 · answered by bequalming 5 · 1⤊ 0⤋
Multiply top and bottom by the conjugate of the bottom.
[ 3i • (4-7i)] / [(4+7i)(4-7i)] =
[12i - 21i²] / [16 - 49i²] =
( 21 + 12i) / (16 + 49) =
( 21 + 12i) / 65 =
21/65 + (12/65)i
2007-01-22 03:58:55 · answer #4 · answered by Philo 7 · 0⤊ 0⤋
The FOIL approach. First, outdoors, interior, very last. clone of the different polynomial simplification. for sure i = ?(-a million). So it is going to appear like this: First outdoors interior very last (4)(5) + (4)(-7i) + (3i)(5) + (3i)(-7i) = 20 - 28i +15i - 21i² = 20 - 13i + 21 = 40-one - 13i (simplified)
2016-12-02 21:42:45 · answer #5 · answered by Anonymous · 0⤊ 0⤋
3i/(4+7i) = 0
3i = 4+7i
3i - 7i = 4
-4i = 4
i = 4/-4 = 1
2007-01-22 03:53:05 · answer #6 · answered by Layla 3 · 0⤊ 0⤋
multiply both top an bottom by (4-7i)
Then you will get (3i)*(4-7*i)/[(4+7i)(4-7i)]
You can do the rest
2007-01-22 03:54:21 · answer #7 · answered by sparrowhawk 4 · 0⤊ 0⤋
multiply both top and bottom by 4-7i
3i(4-7i)/(4+7i)(4-7i) = (12i+21)/(16+49) = (21+12i)/(65)
2007-01-22 03:54:39 · answer #8 · answered by kellenraid 6 · 0⤊ 0⤋