Question

24.If l, m, and n are all parallel, solve for x.x + 51012.8x-3m12A. 11B 13c.15D14

Answer 1

Using the ratio of the parallel sides, we have

`(x+5)/(12.8)=(10)/(x-3)`

Simplify by cross multiplying the fraction

`\begin{gathered} (x+5)(x-3)=10*12.8 \\ x^2-3x+5x-15=128 \\ x^2+2x-15-128=0 \\ x^2+2x-143=0 \end{gathered}`

The leads to a quadratic equation, which will be solved using the factor method

`x^2+13x-11x-143=0`

By binomial factors, we have

`\begin{gathered} x(x+13)-11(x+13)=0 \\ (x+13)(x-11)=0 \end{gathered}`

Then equate each expression to 0, we obtain

`\begin{gathered} x+13=0\text{ 0r X-11=0} \\ x=-13,11 \end{gathered}`

Therefore x=-13,11