I have three math question i 'm having problem on my homework. If c=5/6 and d=1/4 Evaluate: 8c/-d?

Question

Solve the equation for b: -8/63b=-4/9.

Solve the equation for n:b 3/5=9/10b

All the question or faction.

Answer 1

3/5*10/9 = 2/3; 9/3 = 3 & 10/5 = 2; so b = 3/2 or 1-1/2.

I don't think you wrote the first problem correctly...I think it is supposed to ber: 8/3b = 4/9. The negatives are going to cancel each other out, so we can ignore them.

so, then you have b = 4/9*3/8 = 4/8*3/9 = 1/2 * 1/3 = 1/6.

Answer 2

For the first problem:

[8x(5/6)] / -(1/4) = (40/6) / - (1/4) = 40/6 x (-4/1) = -160/6 (simplify by 2)= -80/3

Second:

-(8/63b) = -(4/9) you have to cross multiply which gives you -(8x9) = -(63bx4) you can multiply both sides with (-1) to get rid of the negative sign (in other words the negative sign can be eliminated 1=1 is the same with -1=-1) this gives you 72= 252b
b=72/252 which can be simpplified with 36 thus b is 2/7

Third goes the same way:

3x10b = 5x9 , 30b= 45 , b= 45/30 simplify with 15, b= 3/2

Answer 3

Evaluate 8c/d, You are suppose to just plug in for c and d. So (8)x(5/6) / (1/4) and find the solution. Which would most likely be 80/3.

For 3/5=9/10b. ...all you do is (3/5) / (9/10) and it should equal (2/3)

For -8/63b=-4/9.... all you do is (-4/9) / (-8/63) = b and so b = (7/2)

Just some basic rules for fractions
Multiplying

(a/b)x(c/d)= (ac/bd)

Dividing

(a/b) / (c/d)= (ad)/ (bc)

Adding or Subtracting

(a/b) + (c/d) = ((ad) + (cb)) / (bd)
(a/b) - (c/d) = ((ad) - (cb)) / (bd)

Answer 4

8c/-d = (40/6)/(-1/4) = (20/3) x -4 = -80/3, 26 2/3

-8/63b = -4/9 (- cancels out on both sides)
b = (4/9)/(8/63) = (4x63)/(8x9) = (1x7)/(2x1) = 3 1/2

b = (3/5)/(9/10) = (3x10)/(9x5) = (1x2)/(3x1) = 2/3. not sure what n:b is; maybe n:2/3 ??

Answer 5

8c/-d = 8*5*(-4)/6 = -160/6

b= (63*4) / (9*8)

can't decipher the last one?

if 3/5 = 9/10b then (3*10) / (5*9) = b

Answer 6

well, 8x5/6 equals 20/3. divide by -d so 20/3x-4 since the reciprocal of d is 4. 20/3x-4 equals (20x-4 or -80) -80/3.

Answer 7

do ur own homework gosh!