College algebra help?

Question

im taking an online course and out of the 220 problems they assigned to get done in 3 days, ive managed to answer all but about 12. so i am posting 4 here. Please help me with all of them if you can, if you can only help me with 1 or 2 no big deal its still much appreciated. thank!


1)i=prt, solve for p

2)y=mx+b solve for m

3)(ab)/c = d/e solve for e

4)a + b = 3 (r + r *sub one*)b solve for r sub one

Answer 1

prt=i
p=i/rt [dividing both sides by rt
2)mx+b=y
or.mx=y-b
or, m=(y-b)/x [dividing both sides by x]
3)ab/c=d/e
or,abe=cd [by cross multiplication]
or,e=cd/ab [dividing both sides by ab]
4)3(r+r1)b=a+b
r+r1=(a+b)/3b
r1={(a+b)/3b}-r

Answer 2

1) i=prt. Since everything is multiplication, just take the 'rt' and divide it both sides to get (i/rt)=p

2) y=mx+b. Now there is addition in the equation. Balance the equation to isolate 'm'. Therefore, subtract 'b' from both sides to get y-b=mx. Now divide x on both sides to get (y-b)/x=m.

3) (ab)/c=d/e. This is almost the same as number one. Isolate 'd' by multiplying by its reciprocal, 1/d. this way you will get (ab)/(cd)=1/e. This equation is not simplified yet, so to get 'e' you need the reciprocal of it, or just 'e'. If 1/e=(ab)/(cd) then e=(cd)/(ab)

4) a + b = 3(r+r'sub1'). First, isolate (r+r'sub1'), that means divide three on both sides to get (a+b)/(3)=r+r'sub1'. Now just subtract 'r' on both sides to get 'r'sub1''. This translates into: ((a+b)/(3))-(r)=r'sub1'

I hope this has helped you

Answer 3

i = prt this is the general formula for interest calculation

You need to get the variable p by itself

divide each side of the equation by r t

p = 1 /rt

y = mx + b is the equation for a straight line with a slope of m

as before we need to get m by itself

subtract b from each side

y-b = mx

divide each side by x

m = y-b/ x

ab/c = d/e

multiply both sides by e

e(ab)/c = d

multiply both sides by c

e(ab) =cd

divide both sides by ab

e = cd / ab

a + b = 3(r + 1/r)b

divide each side by 3b

a + b/ 3b = r + 1/r

subtract r from each side

a + b / 3b - r = 1/r

Answer 4

1)i=prt, solve for p
p= i/rt

2)y=mx+b solve for m
m= (y-b)/x

3)(ab)/c = d/e solve for e
abe = cd
e = cd/ab

4)a + b = 3 (r + r *sub one*)b solve for r sub one
a+b = 3r + 3r1
a+b-3r = 3r1
(a+b-3r)/3 = r1

Answer 5

1) p=i/rt
2) mx=y-b
m=(y-b)/x
3) ab/c=d/e cross multiply
abe=cd
e=cd/ab
4) a+b=3r+3r(s1)
a+b-3r=3r(s1)
(a+b-3r)/3r=r sub 1

Answer 6

1) p=i/(rt)
2) m= (y-b)/x
3) e= (cd)/(ab)
4) r sub one = (a+b)/3b - r

Answer 7

p = i/rt
m=(y-b)/x
e=dc/ab
r1= (a+b -3br)/3b