For this case we have the following expression:
We follow the steps below:
We subtract 4x on both sides of the equation:
We subtract 10 from both sides of the equation:
Now, we must complete squares.
When we have an equation of the form:
, if we want to complete squares we must subtract c on both sides of the equation obtaining:
The square is completed by adding to both sides of the equation: 
So, we have left:
In the given expression we have:
And to complete the square we have:
Rewriting we have:
We factor the left side of the equation, that is, we look for two numbers that when added together result in -8 and when multiplied as a result 16. We have:
So, we have:
Answer:
The intermediate step is to complete squares
DO NOT GO TO THAT LINK IT IS A VIRUS
Sure 32.144 devided by 9.8
Answer: (3b + 5)(3b - 5)
Because both terms, 9b² and 25, are perfect squares, you can factor by taking the square roots of both terms.
The square root of 9b² is 3b (3b × 3b = 9b²).
The square root of 25 is 5 (5 × 5 = 25).
9b² - 25 has a negative, so the factored expression would be
(3b + 5)(3b - 5). The signs (+ and -) alternate in this case because the expression, 9b² - 25, has no middle term.
You can check your work by using FOIL. See the attachment below.
F irst
O utside
I nside
L ast
I hope this helps you
if 2 cm 21 km
9cm ? km
?×2=9×21
?=189÷2
?=94,5 km
