F(2)=4(2)+5
f(2)=8+5
f(2)=13
Just subsitute 8 for n
1/2(8)^2-1/2(8)
1/2(64)-4
32-4
28
D
In rectangle ABCD
AB * AC = area
In another rectangle WXYZ
WX * WY = area
The sides must be equal or have same multiples and should be divisible by each other
Answer:
x = - 7, y = 6
Step-by-step explanation:
7x + 7y = - 7 -----> equation 1
- 10x - 7y = 28 -----> equation 2
Add equations 1 & 2,
7x + 7y = - 7
- 10x - 7y = 28
___________
- 3x + 0 = 21
- 3x = 21
x = 21 / - 3
x = - 7
Substitute x = - 7 in equation 1,
7x + 7y = - 7
7y + 7x = - 7
7y + 7 ( - 7 ) = - 7
7y - 49 = - 7
7y = - 7 + 49
7y = 42
y = 42 / 7
y = 6
