8. Karen makes $5 per hour babysitting and $12
per
hour giving music lessons. One weekend, she
worked a total of 18 hours and made $139. How
many hours did she spend babysitting?

Respuesta :

Karen spend 11 hrs doing babysitting and 7 hrs doing music lessons by solving the linear equation.

What is system of linear equation ?

A linear equation is one that has a degree of 1 as its maximum value. No variable in a linear equation, thus, has an exponent greater than 1. A linear equation's graph will always be a straight line.

A linear equation is an algebraic equation in which each term has an exponent of 1, and which, when plotted on a graph, always yields a straight line. It is called a "linear equation" for this reason.

Both linear equations with one variable and those with two variables exist.

Ax + B = 0, where A and B are both real integers, and x is the only variable, is the standard form or general form of a linear equation in one variable. Ax + By = C is the formula used to describe linear equations with two variables, where x and y are the variables and A, B, and C are any real values.

Total number of hours babysitting and music lessons be x and y hrs respectivly.

Therefore x + y = 18             (i)

and, 5x + 12y = 139              (ii)

Multipling equation (i) with 5 then subtracting from (ii) we get,

5x + 12y - 5x - 5y = 139 - 90

⇒ 7y = 49

⇒ y = 7.

When y = 7 putting this value in equation (i) we get x = 11.

Karen spend 11 hrs doing babysitting and 7 hrs doing music lessons.

To learn more about Sysyem of linear equation refer to :

https://brainly.com/question/10049376

#SPJ1

ACCESS MORE