Answer: We should add the constant 81 to the expression to have a perfect square trinomial.
The perfect square trinomial that would be formed would result from (x + 9)^2.
We can use foil to prove it.
(x + 9)(x + 9)
x^2 + 9x + 9x + 81
x^2 + 18x + 81
81 is the value that must go with 18x in the middle to form the perfect square trinomial.
Answer:

Step-by-step explanation:
<em>Hey there!</em>
Well to add this we need to pu it in improper form.
7/5 + 23/4
Now we need to find the LCM.
5 - 5, 10, 15, 20, 25, 30
4 - 4, 8, 12, 16, 20, 24, 28
So the LCD is 20.
Now we need to change the 5 and 4 to 20.
5*4 = 20
7*4 = 28
<u>28/20</u>
4*5=20
23*5=115
<u>115/20</u>
Now we can add 28 and 115,
= 143/20
Simplified
7 3/20
<em>Hope this helps :)</em>
Answer:
4 dozens
Step-by-step explanation:
<em>Find Eleanor and Joanna's ratio of eggs to milk</em>
Eleanor:
<em>Dozen eggs : gallons of milk</em>
9 : 3
3 : 1
Joanna:
<em>Dozen eggs : gallons of milk</em>
2 : 2
1 : 1
<em>They gather one gallon of milk each which means Joanna has 1 dozen eggs and Eleanor has 3 dozens of eggs.</em>
Total dozen of eggs = 3 + 1 = 4
Therefore, total dozen of eggs the family have per week is 4 dozens.
for number 19, figure out the exponents then multiply.
for scientific notaintion you figure out how many numbers are behind the decimal , then do that number as an exponient to 10 then multiply by that number. i hope i made a bit of sense. if not look at kahn academy for help !