It says it clearlyit says it must include appetizers a main course dessert beverage and water
5x - 2 = 8x + 5.
-2 = -5x + 8x + 5
-2 = 3x +5
-7 = 3x
-7/3 = -2.3
Answer:
- x +y = 500
- 0.65x +0.95y = 0.75(500)
- solution: (x, y) = (300, 200)
Step-by-step explanation:
A system of equations for the problem can be written using the two given relationships between quantities of brass alloys.
<h3>Setup</h3>
Let x and y represent the quantities in grams of the 65% and 90% alloys used, respectively. There are two relations given in the problem statement.
x + y = 500 . . . . . . quantity of new alloy needed
0.65x +0.90y = 0.75(500) . . . . . quantity of copper in the new alloy
These are the desired system of equations.
<h3>Solution</h3>
This problem does not ask for the solution, but it is easily found using substitution for x.
x = 500 -y
0.65(500 -y) +0.90y = 0.75(500)
(0.90 -0.65)y = 500(0.75 -0.65) . . . . . . subtract 0.65(500)
y = 500(0.10/0.25) = 200
x = 500 -200 = 300
300 grams of 65% copper and 200 grams of 90% copper are needed.
First you add like terms which means you add all the x's together and all the constants.
3x -5 =55 (Remember that 8 has a negative sign in front which brings that sign with it when combinding like terms)
Then you isolate the variable by adding 5 on both sides.
3x = 60.
Finally you divide by 3 on both sides to get x=20