why are my questions not showing up?

Question

A gourmet food shop mixes nuts selling at $16/lb with fruit selling at $3/lb. They want a mixture of 7 lb. to sell at $12/lb. How many pounds of each should they use?

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I have no idea what to do. Wow, I feel so dumb :(

Gawsh watch this one not show up either

Answer 1

say total nuts=x
and total fruit=y
then,
the equation 16x+3y=84
x+y=7
x=7-y
plug in (1)
16(7-y)+3y=84
112-16y+3y=84
112-13y=84
-13y=--28

y=28/13=2.15

plug in
x=7-28/13
=91-28/13
=63/13
=4.85
hope this helps

Answer 2

Your question showed up just fine.

Let

x = lbs of nuts
y = lbs of fruit

x + y = 7 (total number of lbs)

To calculate cost, multiply the number of lbs by the cost per lb.

16x + 3y = 7(12) = 84

So now you have two equations and two unknowns.

x + y = 7
16x + 3y = 84

Subtract three times the first equation from the second.

13x = 84 - 3*7 = 84 - 21 = 63
x = 63/13 lbs of nuts

y= 7 - x = 7 - 63/13 = 28/13 lbs of fruit

As a check the price should average $7/lb

Price = 16(63/13) + 3(28/13) = (16*63 + 3*28)/13
= 1092/13 = $84

Average price = $84/7 lb = $12 / lb

Answer 3

Set up a two-variable, two-equation system with
n = the number of pounds of nuts used
f = the number of pounds of fruit used.

The total weigth of the mixture should be 7lbs, so your first equation is
n + f = 7

The total price of the mixture should be $84 (7 pounds at $12/lb), so the second equation is
16n + 3f = 84.

Solve for n and f.

Answer 4

Let n = pounds of nuts, f = pounds of fruit

16n+3f=12(7)=84
n+f=7

n=7-f

Substitute this into the first equation:
16(7-f)+3f=84

112-16f+3f=84

112-13f=84

-13f=-28

f=28/13 pounds

n=7-f = 7-28/13 = 91/13-28/13=63/13 pounds

Answer 5

the equation 16*x+3*y=84
x+y=7
x=7-y
sub in (1)
16(7-y)+3y=84
112-16y+3y=84
112-13y=84
adding -28
-13y=--28
y=28/13=2.15
sub x=7-28/13
=91-28/13
=63/13=4.85

Answer 6

well it did show up