7:05, 7:15 , and 7:12 i hope this helps
Understand that a decimal is any number written in the base-10 system. In common usage, the term "decimal" refers to a number that uses a decimal point to separate the ones place from tenths, hundredths, etc. Represent decimals using area models. State the fraction (tenths or hundredths) that is equivalent to a given decimal. Compare the values of decimals (tenths or hundredths) using area models and/or a number line. For example, compare the value of 0.8 and 0.21.Find a decimal that has a value between two other decimals. For example, find a decimal with a value between 0.3 and 0.4.
we have
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
therefore
the answer is
the solutions are
Answer:
a) 820
b)450
c) -540
d) -294
e) 1440
f) 1425
Step-by-step explanation:
a) it is an arithmetic progression with ratio=4
a1=3,
a2=3+r=3+4=7.....
a20=a1+19r
so a20=3+19*4=3+76=79
S=(a1+an)*n/2 where n=20
so S=(3+79)*20/2=820
b) a15=a1+14*r=2+14*4=2+56=58
S=(a1+a15)*15/2=(2+58)*15/2=60*15/2=30*15=450
It is the same formula for all the exercises
S=(a1+an)*n/2 , where n is the number of terms
c) a40=30+39*(-3)=30-87=-57
So S=(30-57)*40/2=-540
d) a14=5+13*(-4)=5-52=-47
S=(5-47)*14/2=-42*14/2=-42*7=-294
e) it is 5+7+9+......+75
nr of terms = (an-a1) :r+1=(75-5):2+1=36
S=(5+75)*36/2=36*40=1440
f) ratio=7-4=3
the same formula for n= (91-4):3+1=87:3+1=29+1=30
S=(4+91)*30/2=95*30/2=2850/2=1425
