Help with Algebra?

Question

Any assistance would be nice.

P = A / (1 + rt)
Solve for r.

A = 1/2h (B + b)
Solve for B.

P = A / (1 + rt)
Solve for t.

P = Fd / t
Solve for t.

A painter can finish painting a house in 3 hours. Her assistant takes 5 hours to finish the same job. How long would it take for them to complete the job if they were working together?

Mark and Rachel both work for Smith Landscaping Company. Mark can finish a planting job in 4 hours, while it takes Rachel 5 hours to finish the same job. If Mark and Rachel work together on the job, and the cost of labor is $40 per hour, what should the labor estimate be?

Answer 1

P = A / (1 + rt )

Step 1: Cross-multiply to get rid of the division. You should get A = P + Prt.
Step 2: You need to work to get r by itself. To do this you must subtract P from each side. You should now get A - P = Prt.
Step 3: Now all you must do is divide each side by Pt. You should now have (A - P) / Pt = r.

Therefore, your answer is: r = (A-P)/Pt

A = 1/2h (B + b)

Step 1: Divide each side by 1/2h, so you should get A / (1/2h) = B +b.
Step 2: Now all you have to do is subtract b from each side. You get [A / (1/2h)] - b = B.

Your answer is: B = [A/(1/2h)] -b.

P = A / (1 + rt)

**This problem is like your first, so you're going to be following the same steps as outlined in the first problem, only you're now solving for t.

Step 1: Cross-multiply to get rid of the division. You should get A = P + Prt.
Step 2: You need to work to get t by itself. To do this you must subtract P from each side. You should now get A - P = Prt.
Step 3: Now all you must do is divide each side by Pr. You should now have (A - P) / Pr = t.

The answer is: t = (A-P)/Pr

P = Fd / t

Step 1: Cross-multiply. You get Pt = Fd.
Step 2: Now all you need to do is divide each side by P. You're left with t = (Fd)/P.

The answer is: t = (Fd)/P.

***You apply the steps above in order to answer the two word problems. Write algebraic expressions for each, and solving them should be a breeze.

Answer 2

P = A/ (1+rt)
multiply (1+rt) by both sides
so now you have...
P(1+rt) = A
put it into parts like so...
P(1) + P(rt) = A
Then multiply it out
P +Prt = A
Subtract P by both sides
0 + Prt = A + P
then divide Pt by both sides like so...
Prt / Pt = (A + P)/ Pt
then you get your answer
r= (A + P)/Pt
and if you wanna go further mutiply the parts out ...
r = A/Pt + 1/t

Do this with the next 3 and you'll get the idea of this equation.

Answer 3

what? you want us to do your homework?