First set up your two equations:
x + y = 90
x = 2y - 30
Then substitute what x equals in the second equation into the first equation:
(2y -30) + y = 90
Now solve for y:
3y -30 = 90
3y = 120
y = 40
Then use y = 40 and substitute the value for y into one of your original equations and solve for x. I'll choose the first one, but either one will work.
x+ 40 = 90
x = 50
So your solution is x = 50 and y = 40
Answer:
-5
Step-by-step explanation:
4x0.5=2
2x0.5=1
2+1=3
3-8=-5
Using the graph that is included, look at the points given. For example (30, 3). There would be 30 vegetarian dishes and 3 steak dinners for a total of 33 meals. If that is plugged into the cost equation 20(30)+3(30) it would equal $690. The next point (33, 1) would cost 20(33) + 30(1) = $690 and but gives 34 meals. However, 34 vegetarian meals would only cost 20(34)=$680 and have 34 meals.
If both types of meals need to be purchased, 33 vegetarians and 1 steak. If only vegetarians are purchased, the cost is cheaper by $10.
On number 2 2 times -3 is 6
