Strange math problems(for me)??

Question

1) 17% of what is 156

2)30d^2/90d^5 =

3)calculate -3 + 5 - (-5) + 12

4) solve for n: -7(n+3) - 8(1 + 8n)

5) solve for x: -6 + x/4 = -5

6) solve for b: 7/b+5 = 10/5

Answer 1

1) 917.647 (to 3 decimal places)

2) Not sure!

3) 19

4) n = -(29/71)

5) x = 4

6) 7/b = -3

Answer 2

1. Let what be x

(17%/100%)*x=156

17x = 15600

x = 917.65

2. 30d^2/90d^5 = 1/(30d^3) = 30d^-3

Basically you cancel out the 30 with 90 to get bottom 3 AND for d^2 with d^5 to get d^3.

3. Calculate -3 + 5 - (-5) + 12

= -3 + 5 + 5 + 12

= 19

A negative negative you get a positive.

4. solve for n: -7(n+3) - 8(1 + 8n)

= - 7n - 21 - 8 - 8n

= -15n -29

A negative with a positive gives you a negative.

5. solve for x: -6 + x/4 = -5

Multiply all numerals with 4,

-24 + x = - 20

x = 4

The 4 from x/4 cancels out.

6. solve for b: 7/b+5 = 10/5

Same method as question 5

Multiply with 5b

35 + 25b = 10b

15b = -35

b = -2.33

Answer 3

dude, you can do it on a calculator.