A) get rid of the parenthesis 4(5n-7) = 20n-28,
so 20n-28=10n+3===>transpose 10n from the left to the right it becomes -10n & transpose -28 from the left to the right it becomes +28
10n=31 & n=31/10 ==> n=3.1
Answer:
see below
Step-by-step explanation: 5 20 15 28
3x + y = 23
3x – 2y = 8
O I should add, and the Xs will be eliminated. 3x + 3x = 6x NOT eliminated
O I should add, and the Ys will be eliminated. y + -2y = -y NOT eliminated
O I should subtract, and the Xs will be eliminated. 3x - 3x = 0x X is eliminated
O I should subtract, and the Ys will be eliminated. y - -2y = y NOT eliminated
Ok lets say
popcorn = x and
drinks = y
Jacob: 2x + 3y = 18.25
Zachary: 4x + 2y = 27.50
ok now you have to use these 2 equations to get the answer
4x + 2y = 27.50 ---> 2y = 27.50 - 4x ---> y = 13.75 - 2x
2x + 3y = 18.25
2x + 3(13.75-2x) = 18.25
2x + 41.25 - 6x = 18.25
-4x + 41.25 = 18.25
-4x = -23
x = 5.75 <u><em>One bag of popcorn is $5.75</em></u><em />
4x + 2y = 27.50
4(5.75) + 2y = 27.50
23 + 2y = 27.50
2y = 4.50
y = 2.25 <u><em>One drink is $2.25</em></u><em />
262.5 should be the correct answer though. 105/30=3.5 so the plane is approximately traveling at 3.5 miles per minute. 3.5x60= 210 so at an hour it has traveled 210 miles. Then we must find .25 of an hour which is 15 minutes. 15x 3.5=52.5. Add both the hour value and the .25 of an hour value together and it is 262.5 miles.
