The difference of two numbers,  a  and  b, is 21.  the difference of 5 times  a  and two times  b  is 18.  what are the values of  a  and  b? a.  4, 1b.  -19, 40c.  20, 1d.  30, 9e.  -8, -29

E.  -8, -29

Step-by-step explanation:

a-b=21

5a -2b =18

Take the first equation and solve for a by adding b to each side

a-b=21

a-b+b=21+b

a = 21+b

Now substitute a=21+b into the second equation

5a -2b =18

5(21+b) -2b =18

Distribute the 5

105 +5b-2b =18

Combine like terms

105 +3b =18

Subtract 105 from each side

105-105 +3b = 18-105

3b = -87

Divide each side by 3

3b/3 =-87/3

b = -29

if b = -29, we can substitute it into a =21+b

a = 21-29

a = -8

0.16 or 16%

step-by-step explanation:

lets take a coin for example.

if you toss it twice, it has a 1/4 chance of landing on heads both times because 1/2 * 1/2 is 1/4.

with the cards, the chance of picking dog is 0.4. having two people pick one is like picking a card twice in a row. so 0.4 * 0.4 is 0.16, or 16%

answer: x=3 and y=4

step-by-step explanation: