Answer is (1) 160 km in 2 hours and
(2) 16 miles in 12 minutes.
Step by step.
80 km / 1 hour = x km /2 hours
Cross multiply =
x = 160
The second one requires a little more math. Because we are looking at how far in minutes, we change the rate of 80km in 1 hour to 80 km in 60 minutes.
80 km / 60 = x / 12
Cross multiply
12x = 960
Solve for x by dividing both sides by 12
X = 16
I did the math on a print screen to explain the cross multiply.
We need to find two numbers that multiply to 24 (last coefficient) and add to 10 (middle coefficient). Through trial and error, the two values are 6 and 4
6 + 4 = 10
6*4 = 24
So we can break up the 10ab into 6ab+4ab and then use factor by grouping
a^2 + 10ab + 24b^2
a^2 + 6ab + 4ab + 24b^2
(a^2+6ab) + (4ab+24b^2)
a(a+6b) + 4b(a+6b)
(a+4b)(a+6b)
Therefore, the original expression factors completely to (a+4b)(a+6b)
Answer:
182
Step-by-step explanation:
Sum = a(r^n -1) ÷ r - 1
1(-3^6 - 1) ÷ -3 -1
= 182
r = t2 ÷ t1 * since they stated that it is geometric
All triangles are similar.
.. x/3 = 27/x
.. x^2 = 81
.. x = 9
.. y = √(x^2 -3^2) = √72
.. y = 6√2