Substitute y=4x to the second equation:
x^2 + (4x)^2 = 17
x^2 + 16x^2 = 17
17x^2 = 17
x^2 = 17/17
x^2 = 1
x = 1 and -1
When x=1, y=4(1) = 4
When x=-1, y=4(-1) = -4
Thus the solutions would be (1,4) and (-1,-4). That would correspond to D. and A.
C = Cost To Download
M = Membership Fee.
T = 0.99C + M
Now, Plug In 6 For C.
And 12.49 For M
T = 0.99 * 6 + 12.49
0.99*6 = 5.94
T = 5.94 + 12.49
5.94+12.49 = 18.43
T = 18.43.
So, If You Want To Buy 6 Games On The Website, It Will Cost $18.43
Let, the length be l and breadth be b.
So, 2(l + b) = 26
Or, l + b = 13
Or, l = 13 - b
So, we may write like this,
Area = l * b
Or, l * b > 30
Or, l (13 - l) > 30
Or, 13l - l^2 > 30
Or, l^2 - 13l + 30 > 0
Or, l^2 - 3l - 10l + 30 > 0
Or, l(l - 3) - 10(l - 3) > 0
Or, (l - 3)(l - 7) > 0
Or, l - 7 > 0
Or, l > 7.
Now, putting the value of l,
We get, l * b > 30
Or, 7 * b > 30
Or, b > 30/7
➡️ Therefore, we get,
Length > 7
Breadth > 30/7
That's it..
Answer: X=12
Explanation: 180-72= 108. 108 divided by 9 is 12