Question

In the figure above, two line segments meet at a point on line $l$. If the value of $y$ is equal to the square of the value of $x$, calculate the value of $y$.

• A. $100$
• B. $80$
• C. $60$
• D. $40$
• E. $20$

Answer 1

The correct option is A $100$

Given, two line segments meet at a point on line $l$
We know angle on a straight line is $180$ degree.
So $x+y+70=180$ degree
If the value of $y=$ $x^2$ then the equation will be as
$\Rightarrow x^2+x+70=180$
${\Rightarrow x}^2+x-110=0$
$\Rightarrow x^2-10x+11x-110=0$
$\Rightarrow x(x-10)+11(x-10)=0$
$\Rightarrow (x-10)(x+11)=0$
$\Rightarrow x=10orx=-11$
$\Rightarrow x=10$ as it is positive
So value of $y$ will be$x^2$$=$ ${10}^2=100$.