hi it's kaylee now that we know how to solve one-step equations
it's time to use them in some real world examples let's go
poppy and alex are collecting seashells poppy has collected 14 seashells and alex has collected
x seashells together they have 36 seashells write an equation to describe how many seashells poppy
and alex have how many seashells does alex have so we need to write an equation to describe how
many shells poppy and alex have so one thing i know for certain it will have an equal sign
so i can draw that there now what else do i know for certain i know that together
they have 36 seashells put that on one side of my equal sign
so how many seashells poppy and alex have the total is equal to 36. now how do i describe
how many they have if poppy has 14 and alex has x yeah we would add those two numbers together right
so we would add poppies 14 seashells plus how many alex has which we don't know it's x so here's
our equation that will describe this situation poppy seashells plus alex's seashells equals 36
seashells total now my other question is how many seashells does alex have
so that means i need to solve my equation for this x here so how do i solve for this x
yeah i'm going to take poppies 14. i'm going to subtract them here so i can get alex's all by
itself but that means i also need to subtract it from over here so this will leave me with
this goes to 0 plus x will just be x and 36 minus 14 that gives us 22 but 22 what yeah 22
seashells that alex found so that is our final answer nice work kenny's soccer team is having
a bake sale to raise money for uniforms they need to raise 75 dollars for their uniforms
the team makes 1.50 per cookie they sell write an equation to describe how many cookies the team
needs to sell to meet their goal then solve the equation so let's start by writing down what we
know we know that they need to raise five dollars total so our goal here is seventy five dollars
and we know that each cookie costs a dollar fifty so they make a dollar fifty for every
cookie that they sell and we need to know how many cookies the team will sell so that's kind of our
variable right how many cookies that's what we don't know let's call that variable how about c
for cookies okay so what would happen if kenny's soccer team sold just two cookies so that would
be when c is equal to two so let's say if c is equal to two how much money does the
team make well if they made a dollar fifty for every one that means we would multiply right
we would have one dollar and fifty cents times c would be equal to however much money but if
we know that this c here is equal to two then we would say a dollar fifty times two is equal to
three dollars would be the total right so let's see how that works now if we don't know what c
is this is a mystery let's turn this 2 into a question mark here but we know our goal here is
75 dollars so this equation here will describe kenny's soccer team bake sale when they raise
their goal amount of 75 dollars so let me write it out a little bit cleaner right here
a dollar 50 times c i'm just gonna write it right next to it is equal to 75 but we want to know how
many cookies the team needs to sell so we need to know what this c is this mystery number of cookies
here so if i solve for c how do i get it alone on one side yeah i have to divide right i have to
undo this multiplying so i can use that fraction here i'm dividing by a dollar fifty over here but
that means i need to divide by a dollar fifty over here and that will give me c the number of cookies
is equal to my units cancel out 75 divided by 150 you might not know it off top of your head it's
okay to use a calculator when we're using some decimals down here it's equal to 50 but 50 what
this c means cookies so that is our answer here kenny's team will need to sell
50 cookies in order to make 75 dollars for their uniforms good job now it's your turn to practice
using one-step equations with word problems have fun remember to always be clever