Question

Angela ate at a restaurant four times. Each time she ordered a salad and left a $5 tip. She spent a total of $54. Write and solve an equation to find the cost of each salad.

Answer 1

what do you have to "solve for" ?

Answer 2

solve for the cost of the salads

Answer 3

ok, then in algebra, we give what we are solving for a short "name"
usually "x" (for unknown)

Answer 4

ya

Answer 5

so solve for x salads. But how do i do

Answer 6

if one salad costs x
any idea how much 4 salads will cost ?

Answer 7

ummm idk

Answer 8

it's a way of thinking.

if one salad costs 3 (dollars)
how much does 4 salads cost ? any idea ?

Answer 9

ya but what if it isnt 3 bucks

Answer 10

it dosnt say

Answer 11

just answer the question:
if one salad costs 3 (dollars)
how much does 4 salads cost ? any idea ?

Answer 12

12

Answer 13

now, the thinking part. How did you get 12 ?

Answer 14

3*4

Answer 15

right, and if the cost is x (instead of 3) we *use the same idea*

how much do 4 salads cost if one salad costs x ?

Answer 16

3

Answer 17

i think

Answer 18

how much does 4 salads cost if one salad costs 3
you said 4*3

now use that same idea for
how much does 4 salads cost if one salad costs x

(and remember, you are allowed to multiply a letter)

Answer 19

4*x

Answer 20

yes, or 4x (we usually leave out the multiply sign,but 4x means 4 * x)

Answer 21

aight

Answer 22

now the cost of the meal also included a 5 tip
in other words, the cost of one meal was the cost of the salad x plus the tip 5
can you write that in algebra ?

Answer 23

4x+5

Answer 24

correct?

Answer 25

you wrote 4 salads and 1 tip

but I think she left a tip at each meal
so that is close (but not quite right)

Answer 26

4x+20

Answer 27

correct?

Answer 28

yes, and that equals what ? (they tell you in the question)

Answer 29

54

Answer 30

yes, so you can write an equation showing one side equals the other

Answer 31

what is the cost of each salad tho?

Answer 32

they ask
***
Write and solve an equation
****

we are doing the first part, writing down the equation

Answer 33

so i wrote 4x+20, now what

Answer 34

that is not the whole equation (which must have an = sign)
in other words, it "should make sense" that 4x+20 = what ??

Answer 35

54

Answer 36

yes, so please write down the equation
(which has an equal sign in it)

Answer 37

4x+20=54

Answer 38

correct

Answer 39

yes, that looks good. Try to always write down the whole equation.

now we solve it.

first step is to "add" -20 to both sides, like this
4x+20 -20 = 54-20

now "simplify" both sides.
can you do that ?

Answer 40

no

Answer 41

on the right side you have 54-20
you can simplify that ?

Answer 42

34

Answer 43

and on the left side you have a 20 -20
what is that ?

Answer 44

0

Answer 45

ok, so what does the equation look like now?
try to write it down

Answer 46

34(something)10

Answer 47

4x+20 -20 = 54-20

try again.

Answer 48

4x=34

Answer 49

yes (I assume you know 4x+0 is just 4x)

Answer 50

so thats right??

Answer 51

that equation says: 4 salads cost 34 (dollars)

but using algebra, we divide both sides by 4
can you try doing that?

Answer 52

\[ \frac{4x}{4} = \frac{34}{4} \]

Answer 53

ya

Answer 54

on the left side 4/4 is 1
so you get 1x which we usually write a just x
what do you get on the right side ?

Answer 55

idk

Answer 56

\[ \frac{4x}{4} = \frac{34}{4} \]
x= 34/4

you have to figure out 34/4

Answer 57

8.4

Answer 58

you should write the whole equation
x= 8.40 (add the zero, because this in money)
8 dollars and 40 cents.

Answer 59

so what would be the equation

Answer 60

we figured it out up above. It is what you solved.

Answer 61

4x+20

Answer 62

almost. but that is not an equation
remember it has to have an = sign and another side

Answer 63

4x+20=54

Answer 64

yes

Answer 65

so thats my answer

Answer 66

yes
4x+20=54 is the equation
after you solve it you get
x= 8.40

Answer 67

thx dude, and do you do this for money???

Answer 68

no, an engineer who uses this stuff

Answer 69

thx anyways dude

Answer 70

cya :3