Answer:
2x - 5 = 7
2x -5 + 5 = 7 + 5
2x = 12
2/2x = 12/2
x = 6
Step-by-step explanation:
Answer:
A = πr² ← r is the radius and r = \frac{1}{2} d ← d is the diameter
Hence
π (\frac{1}{2} d)² = A, that is
\frac{d^2\pi }{4} = A ( multiply both sides by 4 )
d²π = 4A ( divide both sides by π )
d² = \frac{4A}{\pi } ( take the square root of both sides )
d = \sqrt{\frac{4A}{\pi } }
Answer: -4
Step-by-step explanation:
Solve 2x+7=-1
2x. =-8
x. =-4
Answer:
29
Step-by-step explanation:
at 9 on both sides to get m alone
-9+m=20
+9. +9
m= 29
Answer:
add, subtract, multiply and divide complex numbers much as we would expect. We add and subtract
complex numbers by adding their real and imaginary parts:-
(a + bi)+(c + di)=(a + c)+(b + d)i,
(a + bi) − (c + di)=(a − c)+(b − d)i.
We can multiply complex numbers by expanding the brackets in the usual fashion and using i
2 = −1,
(a + bi) (c + di) = ac + bci + adi + bdi2 = (ac − bd)+(ad + bc)i,
and to divide complex numbers we note firstly that (c + di) (c − di) = c2 + d2 is real. So
a + bi
c + di = a + bi
c + di ×
c − di
c − di =
µac + bd
c2 + d2
¶
+
µbc − ad
c2 + d2
¶
i.
The number c−di which we just used, as relating to c+di, has a spec
