Answer:
(2,-5)
Step-by-step explanation:
See attachment
One can also solve this by calculation:
y=2x-9
y=-2x-1
-
Rearrange either equation to find x. I'll use the first:
y=2x-9
2x = y+9
x = (y+9)/2
Now use this value of x in the second equation:
y = -2x-1
y =-2((y+9)/2)-1
y = (-2y-18)/2)-1
y = -y -9 - 1
2y = -10
y = -5
Now use -5 for y in the rearranged equation:
y = -2x-1
-5 = -2x-1
-2x = -4
x = 2
Solution is (2,-5)
But the question wants a graph solution, which is also fun when you use DESMOS.
3(-2y+11)-7y=-32
-6y+33-7y=-32
-13y+33=-32
-13y=1
y=-1/13
Answer:
1) The 15%-off coupon is $3.
2) The cost of the meal after the discount is $17.
3) The final cost of the meal with taxes is $18.19.
Step:
1) To find the discount, try to find the amount of 1%, (20÷100 x 15 = 3)
2) To find the cost of the meal after discount (20-3 = 17)
3) To find the final cost, try find the taxes amount (17÷100 x 7 + 17 = 18.19)
4/5 is in its simplest form.