So Serena is 10, and her mother is 3 times ten, so her mother is 30. And if we take 30 minus 10 we will have the age of the mom when Serena was born, which is 20. So we know that when Serena is 20, her mother will be 40. So when Serena is 20, she will be half of her mother's age. 40 × 0.5 = 20.

7 0

4 years ago

A mirror should be centered on a wall. The mirror is 36 inches wide and the wall is 18 feet wide. Which equation helps determine

Lera25 [3.4K]

Linear equation is the equation in which the highest power of the unknown variable is always 1.The equation which helps determine the distance x on each side of the mirror is ,

$x+3+x=18$ .

<h3>Given information-</h3>

The length of the mirror is 36 inches.

The length of the wall is 18 feet.

The linear equation has to find out for the distance <em>x.</em>

<em />

<h3>Linear equation-</h3>

Linear equation is the equation in which the highest power of the unknown variable is always 1.

As one feet is equal to the 12 inches. Thus the length $l$ of the mirror in the feet is,

$l=\dfrac{36}{12}$

$l=3$

The mirror is 3 feet wide.

The distance on each side of the mirror is <em>x. </em>This distance is equal at both side as the mirror is centered. The distance on each side of the mirror is,

$=x+x$ .

Now the the wall is 18 feet wide which is equal to the distance each side of the mirror and the distance of the mirror. As the mirror is 3 feet wide. Thus the equation which determine the distance x on each side of the mirror can be given as,

$x+3+x=18$

Hence the equation which helps determine the distance x on each side of the mirror is ,

$x+3+x=18$ .

Learn more about the linear equation here;

brainly.com/question/2263981

7 0

3 years ago