Answer:
A. Z = 2 + N13
Step-by-step explanation:
Let's solve your equation step-by-step.
0=z2+4z−9
Step 1: Subtract z^2+4z-9 from both sides.
0−(z2+4z−9)=z2+4z−9−(z2+4z−9)
−z2−4z+9=0
For this equation: a=-1, b=-4, c=9
−1z2+−4z+9=0
Step 2: Use quadratic formula with a=-1, b=-4, c=9.
z=
−b±√b2−4ac
2a
z=
−(−4)±√(−4)2−4(−1)(9)
2(−1)
z=
4±√52
−2
z=−2−√13 or z=−2+√13
Answer:
15ft
Step-by-step explanation:
a^2 + b^2 = c^2
12 or 9 can equal to b or a
12^2 + 9^2 = c^2
144 + 81 = c ^2
225 = c^2
Square root of 225
15 = c
I believe B . Because it seems equivalent
