f(x)= x^2 -6x +21
0 =x^2-6x+21
subtract 21 from each side to prepare for completing the square
-21 = x^2 -6x
completing the square (b/2)^2
(-6/2) ^ =3^2 = 9
add 9 to each side
-21 +9 = x^2 - 6x + 9
-21 +9 =(x-3) ^2
-12 = (x-3)^2
take the square root of each side
+- sqrt(-12) = x-3
add 3 to each side, take out the negative inside the square root
3 +- i sqrt(12)=x
simplify the square root sqrt(12)= sqrt(4)sqrt(3) =2sqrt(3)
3 +- i 2sqrt (3) = x
Answer: 3+2isqrt(3)
3-2isqrt(3)
Answer:
a. 5 hours
b. 40 kph
Step-by-step explanation:
300 km ÷ 60 km = 5 hours
200 km ÷ 5 hours = 40 kilometers per hour
Answer: y = 1x+ -2 or y=x-2
Step-by-step explanation:
y=mx+b
-10=1(-8)+b
-10=-8+b
b=-2
Answer:
12%
Step-by-step explanation:
288/2400 *100
=288/24
=12%
Answer:
The solution of the given equations are (3,2).
Step-by-step explanation:
Given equations are :
3d−e=7 ...(1)
d+e=5 ...(2)
Add equations (1) and (2) we get :
3d-e+d+e=7+5
4d = 12
d = 3
Put the value of d in equation (2).
3+e=5
e = 2
So, the value of d = 3 and e = 2. Solution of the given equations are (3,2).
