Question

x+21 10
----- = ------
10 x

find x?

Answer 1

\[\begin{array}{l} \text{Multiply both sides by }x \\ \frac{1}{10} x (x+21)=10 \\ \text{Expand out terms of the left hand side:} \\ \frac{x^2}{10}+\frac{21 x}{10}=10 \\ \text{Divide both sides by }\frac{1}{10} \\ x^2+21 x=100 \\\end{array}\]
\[\text{Can you continue?}\]

Answer 2

I got there by u wasn't sure how to finish

Answer 3

you need to make it like a quadratic equation then factor,
\[x^2+21x=100\]
\[x^2+21x-100=0\]
\[(x+25)(x-4)=0\]
Set each bracket =0 and solve for x

Answer 4

oh, ok. so x=4 because length cant be negative?

Answer 5

yes

Answer 6

thanks

Answer 7

welcome