I need some math help please.?

Question

If x=y and a<b, then

a. a + b = b + y

b. a + x < b + y

c. a + x > b + y

d. a + x = b

e. a + x = y

2. If a<b and c<d, Then

a. ac = bd

b. a = d

c. b = c

d. a + c > b + d

e. a + c < b + d

3. If k<m and x=y, then

a. k-x > m-y

b. k+x = m+y

c. k-x < m-y

d. k+y = m+x

e. kx = my

4. If a=b and x>y, then

a. a-x = b-y

b. a-x > b-y

c. a-x < b-y

d. a+x = b+y

e.a+y = b+x

5. If x<y, z= x/2, and a= y/2, then

a. z < a

b. a > z

c. a = z

d. 2a > y

e. 2x > 2z

How do you do these? I can understand so an explanation would help. Thanks! :)

Answer 1

You just substitute the letters for values.   If you change the values of x &amp; y= 10 each, &amp; B is 5 &amp; A is 3. then you have a whole new ball game as obviously, then B could be only correct choice 15 is greater than 8.  

So if only one answer is correct, then go with B

Answer 2

What I would do for all of them is simply put a number for each variable. Just make sure it follows the orders. (&lt;,&gt;)

Short version: Have a=1, b=2, and so on (they can be any numbers...)

#1: B, because if you follow what I have above, then 1+3&lt;2+3

#2: E, (if a=1,b=2,c=3,d=4)

#3: C: (if k=1,m=2 and x/y = 3)

#4: C: (same as always)

#5: A: (x=2,y=4,z=1,a=2)

There you go, hope this helps.