4 pcs of pies + 5 pcs of pizza cost $23.80. If he buys 2 pc of pies + 7 pcs of pizza, he needs $7 more. How much each pie costs?
How much each pizza costs? I managed to get the cost for 2 pies and pizza but how do I know whether pies and pizza are of the same price?
2006-07-19 22:21:09 · 9 answers · asked by thunderball 1 in Education & Reference ➔ Homework Help
Pizza = $4.20 Pie = $0.70
p=pie z=pizza
4p+5z=23.80
2p=7z=30.80
multiply 2nd one by -1
4p+5z=23.80
-4p-14z=-61.6
add together
-9z=-37.80
z=4.20
4p+(5*4.20)=23.80
4p=23.80-21
4p=2.80
p=0.70
2006-07-19 22:34:01 · answer #1 · answered by ? 4 · 0⤊ 0⤋
5 pens + 5 pencil = $7 5 (y) + 5 pencil = $7 5 pencil = 7 - 5y a million pencil = 7/5 -7 Janet has S Gave away S/2 +a million Gave away (S/2-a million)2 + 2 S - S/2 +a million - S/4 -a million/2 +2 = 5 S/4 + 5/2 = 5 S/4 = 7.5 S =30 So she had 30 stickers in the beginning up
2016-10-08 03:02:01 · answer #2 · answered by ? 4 · 0⤊ 0⤋
4x + 5y = 23.8
2x + 7y = 30.8
2x = 30.8 - 7y
4x = 61.6 - 14y
61.6 - 14y + 5y = 23.8
9y = 37.8
y = 4.2
4x + (5*4.2) = 23.8
x = 0.7
pizza costs $4.20
Pie costs $0.70
Personally i'd go for the pie. much better value for money.
2006-07-19 22:37:54 · answer #3 · answered by well_clever_i_am 3 · 0⤊ 0⤋
4pi + 5pz = $23.80
2pi + 7pz = $30.80
so from first, pz = (23.80-4pi)/5
substituting into 2nd
2pi + 7((23.80-4pi)/5) = 30.80
there's a start, you take it from there
2006-07-20 05:01:17 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Let, x=cost of pies
y=cost of pizza
4x+5y=$23.80 (equation 1)
2x+7y=$23.80+$7 (equation 2)
Solution:
By elimination:
4x+5y=$23.80
4x=-5y+$23.80
x=-5y/4+$5.95
By substitution:
Solve for y=?
2(-5y/4+$5.95)+7y=$30.80
-5y/2+$11.90+7y=$30.80
-5y/2+7y=$30.80-$11.90
9y/2=$18.90
2/9(9y/2)=2/9($18.90)
y=$4.2 (cost of pizza)
Solve for x=?
2x+7y=$30.80
2x+7($4.2)=$30.80
2x+$29.4=$30.80
2x=$30.80-$29.4
2x=$1.4
x=$0.7 (cost of pies)
Check:
2x+7y=30.80
2($0.7)+7($4.2)=$30.80
$1.4+$29.4=$30.80
$30.80=$30.80 (which is correct!)
2006-07-19 23:07:14 · answer #5 · answered by Anonymous · 0⤊ 0⤋
each pie costs $0.70 and each pizza costs$4.2
2006-07-19 22:36:37 · answer #6 · answered by phoenix 1 · 0⤊ 0⤋
pie costs $0.70
pizza costs$4.2
2006-07-19 22:47:20 · answer #7 · answered by Anonymous · 0⤊ 0⤋
4x + 3y=23.8
2x + 7y=30.8
guess and check
2006-07-19 22:26:50 · answer #8 · answered by cmil8 3 · 0⤊ 0⤋
Ahh! TOO... MUCH... MATHS! IT'S... THE... HOLIDAYS!
2006-07-19 22:25:08 · answer #9 · answered by Anonymous · 0⤊ 0⤋