The height $(h)$ $(h)$ of a tree after $(n)$ $(n)$ years is given by the equation $h = 4 n + 7$ $h=4n+7$ . In how many years will the height be 39 feet?

Question

The height $(h)$ $(h)$ of a tree after $(n)$ $(n)$ years is given by the equation $h = 4 n + 7$ $h=4n+7$ . In how many years will the height be 39 feet?

2 Answers

Impact of this question

1935 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-06-23T19:46:30

$n = 8$ $n=8$

Explanation:

Set $h = 39 = 4 n + 7$ $h=39=4n+7$

Subtract 7 from both sides

$39 = 4 n + 7 dddd \to dddd 39 - 7 = 4 n + 7 - 7$ $color(green)(39=4n+7color(white)("dddd")->color(white)("dddd")39color(red)(-7) =4n+7color(red)(-7))$

$dddddddddddddd \to ddddd 32 d = 4 n d + 0$ $color(white)("dddddddddddddd")->color(white)("ddddd")32color(white)("d")=4ncolor(white)("d")+0$

Divide both sides by 4

$32 = 4 n ddddddd \to dddd \frac{32}{4} = \frac{4}{4} n$ $color(green)(32=4ncolor(white)("ddddddd")->color(white)("dddd")32/color(red)(4)=4/color(red)(4) n)$

But $\frac{4}{4}$ $4/4$ is the same as 1 and $1 \times n = n$ $1xxn=n$ giving:

$\frac{32}{4} = n$ $32/4=n$

$\frac{32 \div 4}{4 \div 4} = \frac{8}{1} = n = 8$ $(32-:4)/(4-:4) = 8/1=n=8$

Written as per convention

$n = 8$ $n=8$

Answer 2 · 2018-06-23T19:49:14

$8 years$ $8" years"$

Explanation:

$we have to solve the equation for n$ $"we have to solve the equation for n"$

$4 n + 7 = 39$ $4n+7=39$

$subtract 7 from both sides$ $"subtract 7 from both sides"$

$4 n = 39 - 7 = 32$ $4n=39-7=32$

$divide both sides by 4$ $"divide both sides by 4"$

$(cancel(4) n)/cancel(4)=32/4rArrn=8$

Science

Math

Humanities

... and beyond

The height $(h)$ $(h)$ of a tree after $(n)$ $(n)$ years is given by the equation $h = 4 n + 7$ $h=4n+7$ . In how many years will the height be 39 feet?

2 Answers

Explanation:

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

The height (h)(h)(h) of a tree after (n)(n)(n) years is given by the equation h=4n+7h=4n+7h=4n+7. In how many years will the height be 39 feet?

2 Answers

Explanation:

Explanation:

Related questions

Impact of this question

The height $(h)$ $(h)$ of a tree after $(n)$ $(n)$ years is given by the equation $h = 4 n + 7$ $h=4n+7$ . In how many years will the height be 39 feet?