Answer:
x = 0, -4 and -3.
Step-by-step explanation:
The given expression is "3x to the power of 3 + 21x squared + 36x = 0".
We can write this expression as follows :
Taking 3x common.
x = 3
Hence, the solution of the given quadratic equation are x = 0, -4 and -3.
Answer:
George must run the last half mile at a speed of 6 miles per hour in order to arrive at school just as school begins today
Step-by-step explanation:
Here, we are interested in calculating the number of hours George must walk to arrive at school the normal time he arrives given that his speed is different from what it used to be.
Let’s first start at looking at how many hours he take per day on a normal day, all things being equal.
Mathematically;
time = distance/speed
He walks 1 mile at 3 miles per hour.
Thus, the total amount of time he spend each normal day would be;
time = 1/3 hour or 20 minutes
Now, let’s look at his split journey today. What we know is that by adding the times taken for each side of the journey, he would arrive at the school the normal time he arrives given that he left home at the time he used to.
Let the unknown speed be x miles/hour
Mathematically;
We shall be using the formula for time by dividing the distance by the speed
1/3 = 1/2/(2) + 1/2/x
1/3 = 1/4 + 1/2x
1/2x = 1/3 - 1/4
1/2x = (4-3)/12
1/2x = 1/12
2x = 12
x = 12/2
x = 6 miles per hour
Answer:
-40
Explanation:
Given
u = 2i - j; v= -5i + 4j and w = j
Required
4u(v-w)
4u = 4(2i) = 8i
v - w = -5i + 4j - j
v - w = -5i + 3j
Substitute
4u(v-w)
= 8i(-5i+3j)
= -40(i*i) [since i*i = 1]
= -40
Hence the required solution is -40
784/ 93 = 8.43010752688
93 * <span>8.43010752688 = 784</span>
