I cant figure this out?!?

Question

1) 10x - 6 =7-12 x = ?
2) 3 3/4 + -2 1/8 - -6 2/5 = ?
3) 5(b +a ) = 27b b = ?
4) 31c + cd = -18 c =?

Answer 1

1.
10x-6=7-12x
32x-6=7
32x=13
x=13/32=.40625

2.
3 3/4+(-2 1/8)-(-6 2/5)= 3.75+(-2.125)-(-6.4)= 3.75-2.125+6.4= 8.025

3.
5(b+a)=27b b? Please fix this one.
In case you don't fix it soon, here's my guess at what you meant.
5(b+a)=27b
5b+5a=27b
5a=22b
a=(22/5)b=4.4b

4.
31c+cd=-18c
49c+cd=0
cd=-49c
d=-49

Answer 2

1) 10x - 6 =7-12 10x - 6 = -5 10x=-5+6 = 1 x= 1/10

Now i will explain what I did. First do the 7-12 part to get -5 as you see in the 2nd step then add 6 to both sides as in the 3rd step. Then do the -6 +6 to get 1 now divide both sides by 10 to get x by itself equals 1 over 10.

2) 3 3/4 + -2 1/8 - -6 2/5 = ?

this one is just fractions adding and subtracting. Also know your signs. first the --6 2/5 becomes +6 2/5 and + - 2 1/8 is just - 2 1/8.
now multiply the whole thing by 40 (why 40? because 5*8*4=40 these are the three denominators of the fractions)

we get 40 times [15/4 - 9/8 + 32/5 ] = 150 - 45 + 256= 361

3) 5(b +a ) = 27b b = ?

here we distribute the 5 first to get 5b + 5a = 27b
then subtract 5b from both sides to get:

5b-5b+5a = 27b - 5b
5a = 22b
now divide by 22 to get b by itself to get:
b = 5 a /22

4) 31c + cd = -18
factor out a c to get:
c (31+d) = -18
c= -18/(31+d)
divide both sides by (31+d) to c = bla bla

Answer 3

If you can't figure 1 out, you have PROBLEMS.
The term (7-12)= -5.
Then 10x-6 = -5, so 10x = 1 and x= 1/10.

Don't you remember your fractions? Problem 2 is just an addition; just remember your rule of signs and realize that you may be adding negative numbers and positive numbers.

Problem 3. You won't be able to come up with x=constant, so don't try.
Multiply 5(b+a) out.
Put terms of b on one side and other terms on the other.
Divide both sides by the coefficient of b.

Answer 4

1) x = 7/11

2) -4 and 31/40

3) b = 5a/22

4) c = -18/31 + d