Learn About Applications of Integer Equations

TenMarks teaches you about applications of integer equations.

Learn About Applications of Integer Equations In this particular lesson, let’s learn about how to apply what we’ve learn with addition and multiplication and subtraction and division equations and apply them right application and integer equations. The two problems given to us, the first one I'm going to do here. It says Amy earns $20.00 dollars week, how many weeks does she need to work to earn $400.00 dollars? So Amy earns $20.00 dollars each week. She wants to earn $400.00 dollars. So to earn $400.00 dollars, how many weeks does she need to work? So let say the way we do this is let say the number of weeks that she needs to work to get the $400.00 dollars equals. So needs to work let say n weeks, so what do we know? We know that in one week she earns $20.00 dollars. So $20.00 dollars times n weeks should give her $400.00 dollars, I’m going to put dollar signs on both places. If she works for n weeks at $20.00 dollars a weeks she will get $400.00 dollars. So we have converted this sentence, two sentences into an equation that says 20 times n equals 400. As I can see if the variable is n and I’m multiplying it by a number, this is multiplication equation. So in order to solve this I divide both sides by the number that’s multiplied to n which is 20. So let’s divide left side and the right side by 20. I'm going to takes some space, so what is it gives us 20 over 20n equals 20 and over 20 equals 400 over 20 just cancels out. So n equals 400 over 20, what is 400 divided 20, it’s 20. So n equals 20 weeks. So Amy will have to work 20 weeks to get to $400.00 dollars. That’s the first problem. Let’s look at the second problem. Second problem says the sum of the measures of a triangle is 180 degrees. Find the missing measure. This is the triangle. I'm going to draw line here. Let’s do the second problem this side. This is the triangle given to us. Two angles are 75 and 60 and we need to find the third angle which is X. It’s given that the sum of all the triangles is 180 degrees. So some of the measures of the triangle is 180 degrees, what is that mean? 75 which the first angle plus 60 which the second one plus X which is the third one equals 180. That’s what we’re given, sum of all the measures of a triangle, one, two and three. Some of all of them is 180 we need to find the missing measure. So let’s do this. Let’s add this 75 plus 60 is 135. 135 plus X equals 180. This is the variable that we need to solve for. This is the value that’s being added to it. If it’s being added, I should be able to subtract it from both sides. It’s an addition equation and I should be able to undo it but subtracting the values. So 135 minus 135 is zero plus X equals 180 minus 135 is 45. So X equals 45, let’s replace this with 45. Is this correct? Let’s double check, 70, plus 75 plus 60 is 135. 135 plus 45 is indeed 180. So X equals 45 is indeed the measure of triangle that was missing.