4 kg oranges and 5 kg tomatoes cost 40 $.
10 kg oranges and 10 kg tomatoes cost 90 $.
How many cost a kg of oranges and a kg of tomatoes?
How to solve it?
2006-06-07 12:45:52 · 6 answers · asked by Morena w 1 in Education & Reference ➔ Homework Help
4o+5t=40
10o+10t=90
10t = 90-10o
10t = 10(9-o)
t = 9 - o
4o + 5t=40
4o + 5(9-o)=40
4o + 45 - 5o = 40
-1o = -5
o = 5
10(5)+10t=90
10t=90-50
10t=40
t = 4
to chek
4(5)+ 5(4) = 40
10(5)+10(4)=90
2006-06-07 12:52:04 · answer #1 · answered by Dani 4 · 0⤊ 0⤋
use the subtraction methodon
10 O+10 T= 90
4 O+5 T= 40
then you multiply everything in the second row by two
2 (4 O+5 T= 40) = (8 O+10 T =80)
now place it back into the formula
10 O+10 T= 90
8 O+10 T =80
Now subtract like terms
2 O+ 0 T= 10
solve for O
O = 5
put O back into your original formula to get T
( 4*5 +5 T= 40 ) = ( 20 + 5 T= 40 ) = ( 5T = 20 ) = ( T = 4 )
2006-06-07 13:03:43 · answer #2 · answered by staterules9 3 · 0⤊ 0⤋
a) 4x + 5y = 40
b) 10x + 10 y = 90
do b - 2a
2x = 10
x=5 substitute in a and you get y=4
Oranges are $5 and Tomatoes $4
2006-06-07 12:51:17 · answer #3 · answered by Gerardo G 4 · 0⤊ 0⤋
Set up two equations.
4x+5y=40
10x+10y=90
Then double the top equation.
8x+10y=80 or 10y=80-8x
10x+10y=90
Now replace 10y in the bottom equation with what you got for 10y in the top one.
10x+80-8x=90
Now solve for x. Then plug x in and solve for y.
2006-06-07 12:52:45 · answer #4 · answered by bunstihl 6 · 0⤊ 0⤋
HEY THIS KID ASKED 4 MATH QUESTIONS, STOP GIVING HIM ANSWERS AND MAKE HIM DO A QUESTIONS FOR A CHANGE!!! CHEATER@@@@UUU!!
2006-06-07 12:56:31 · answer #5 · answered by shaqandkobeconnection 3 · 0⤊ 0⤋
i dont know sry, i suck at math. and i hate it too :(
2006-06-07 13:11:25 · answer #6 · answered by Anonymous · 0⤊ 0⤋