Answer:
see explanation
Step-by-step explanation:
given 
To rationalise multiply the numerator/denominator by the conjugate of the denominator
the conjugate of 3 + 7i is 3 - 7i, hence

distribute the numerator/denominator
=
[ note that i² = - 1 ]
= 
= 
=
+
i
=
+
i ← in standard form
Answer:
there is nothing to look at or answer
Answer:
x=13,y=0
Step-by-step explanation:
We are given a system of equations

For equation 1,square all terms to reduce it
√x²+√y²=169
x+y=13
Make x the subject as required by the question to use substitution method
x=13-y
Plug x=13-y into eqn 2
3(13-y)+2y=39
39-3y+2y=39
39-y=39
y=39-39=0
Plug y=0 into equation 1
x+0=13
x=0
Answer:
(-4,0) and (5,0)
Step-by-step explanation:
Factor.
f(x) = x^2 -x - 20
Factors of -20 that when are added they equal -1
-5 and 4
(x-5) (x+4)
x=5 and x=-4