Answer: 
Step-by-step explanation:
GCF = Greatest common factor.
For example: 6 is the GCF of 12 and 18.
The given expression: 
It can be written as
Taking out common factor 
, we get
![5y(x^2-6xy-7y^2)\\\\ =5y(x^2+xy-7xy-7y^2)\ \ [\because-6xy=xy-7xy]\\\\=5y(x(x+y)-7y(x+y))\\\\= 5y((x+y)(x-7y))\\\\=5y(x+y)(x-7y)](https://tex.z-dn.net/?f=5y%28x%5E2-6xy-7y%5E2%29%5C%5C%5C%5C%20%3D5y%28x%5E2%2Bxy-7xy-7y%5E2%29%5C%20%20%5C%20%5B%5Cbecause-6xy%3Dxy-7xy%5D%5C%5C%5C%5C%3D5y%28x%28x%2By%29-7y%28x%2By%29%29%5C%5C%5C%5C%3D%205y%28%28x%2By%29%28x-7y%29%29%5C%5C%5C%5C%3D5y%28x%2By%29%28x-7y%29)
Hence,
Answer:
25.2
Step-by-step explanation:
A calculator will evaluate this for you. If you don't have one, you can use a Google search box.
The Order of Operations tells you to start evaluation with the inner parentheses. Multiplication is performed before addition.
2(7 +2(2.8))
= 2(7 +5.6)
= 2(12.6)
= 25.2
First, 10 1/2 is the same as 21/2
If there are 12 inches in a foot then
21/2*12=126 inches
Answer:
60 miles per hour
Step-by-step explanation:
Consider the structure of the wording: "miles per hour"
The word "per" means for each. There is you clue.
Each is, one of and one of is unit measurement
So the controlling element in this question is that you need to convert the 3 hours into 1 hour.
Using ratio properties
180
3
=
x
miles
1
hour
We need to 'force' the left hand side into the same form as the right. That is: we need to convert the denominator into 1 and see what happens to the numerator.
⇒
180
÷
3
3
÷
3
=
x
1
⇒
60
1
=
x
1
So the unit rate of speed is
60
miles
per
−−−
hour
