Which sums are equal to -9+21? Choose all the correct answers.
A 21 +(-9)
B 9+(-21)
C (-9) + 9 + 12
D -(9 + 21)
E (-9) + (-21)

A, C

Step-by-step explanation:

A and C

Step-by-step explanation:

-9 + 21 = 12

Option A:

21 + (-9)

21 - 9

12 TRUE

Option B:

9 + (-21)

9 - 21

-12 FALSE

Option C:

(-9) + 9 + 12

0 + 12

12 TRUE

Option D:

-(9 + 21)

-(30)

-30 FALSE

Option E:

(-9) + (-21)

-9 - 21

-30 FALSE

Best of Luck!

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.

the total estimated nappy use.=10,500,000

step-by-step explanation:

given that on an average the average baby uses 3528 napkins.

in a particular year 2014, the number of births were 299697 in new south wales.

rounding off the number of births to the nearest hundred thousand we have

no of birtsh = 300000

also rounding off the average usage to nearst thousand we get

average use of a baby = 3500

hence total number of nappy estimated to be used = 3500x300000

= 10,500,000

answer is 10,500,000 nappies