This is the last problem on my homework, and I am stuck with it. I more confused on "setting up" the equation than actually solving it, which usually is fairly simple for me. But if you could include how you "set up" the equation and then the steps to solve I would appreciate it! Thank you and 10 points to the first person who answers!
Surfer Sam purchased a total of 21 items at the surf shop. He bought wax for $3.00 per package and sunscreen for $8.00 per bottle. He spent a total amount of $88.00. How many of each item did he purchase?
Surfer Sam purchased a total of 21 items at the surf shop. He bought wax for $3.00 per package and sunscreen for $8.00 per bottle. He spent a total amount of $88.00. How many of each item did he purchase?
-
ok so first of all, lets call wax=x and sunscreen=y
so
x+y=21, meaning so many wax's + so many sunscreens will equal 21 items
next.
lets do the pricing, using the same variables as above
3x+8y=88, meaning $3per wax times the number of wax bought + $8per sunscreen times the number of sunscreen bought all equal 88.
next rearrange one of the equations for one of the variables.
Let's choose something simple:
x+y=21, so x=21-y
now lets do substitution.
3x+8y=88
3(21-y)+8y=88
63-3y+8y=88
63+5y=88
63-63+5y=88-63
5y=25
y=5
meaning 5 sunscreen were bought, now lets find x.
x+y=21
x+5=21
x+5-5=21-5
x=16
so 16 wax were bought.
lets check to see if we're right
3x+8y=88
3(16)+8(5)=88
48+40=88
88=88 so we're correct!
16 wax and 5 sunscreen!
so
x+y=21, meaning so many wax's + so many sunscreens will equal 21 items
next.
lets do the pricing, using the same variables as above
3x+8y=88, meaning $3per wax times the number of wax bought + $8per sunscreen times the number of sunscreen bought all equal 88.
next rearrange one of the equations for one of the variables.
Let's choose something simple:
x+y=21, so x=21-y
now lets do substitution.
3x+8y=88
3(21-y)+8y=88
63-3y+8y=88
63+5y=88
63-63+5y=88-63
5y=25
y=5
meaning 5 sunscreen were bought, now lets find x.
x+y=21
x+5=21
x+5-5=21-5
x=16
so 16 wax were bought.
lets check to see if we're right
3x+8y=88
3(16)+8(5)=88
48+40=88
88=88 so we're correct!
16 wax and 5 sunscreen!
-
I think its actually multiple equations.
3x + 8y = 88 (This is the equation that shows that the wax is 3 bucks, the sunscreen is $8 and the total was $88)
x + y = 21 (This shows that x and y (the wax and sunscreen total the 21 items he bought).
I was never good at showing my work in math, but the answer is x=16 (wax) y=5 (sunscreen)
3x + 8y = 88 (This is the equation that shows that the wax is 3 bucks, the sunscreen is $8 and the total was $88)
x + y = 21 (This shows that x and y (the wax and sunscreen total the 21 items he bought).
I was never good at showing my work in math, but the answer is x=16 (wax) y=5 (sunscreen)
-
16 wax and 5 sunscreen