Could someone please check my algebra answers?

Question

Problem ONE: Diane took 1 1/2 times as long to complete her project. If Diane needed 9 hours, how long did Amy take to finish her project?
Answer: 7 1/2.

Problem TWO: Maria's pay last week was $585. This was after 1/4 of her pay was taken out for insurance and taxes. How much did Maria have before the deductions?
Answer: Pay before deductions was $731.25.

And I need help figuring out the following answer:
Problem THREE: Joan and Gayle sold 89 magazines. If Joan sold one more than three times what Gayle sold, what was the number sold by Joan?

Thanks for the help in advance!

Thank you so much for explaining that! I really appreciate it and now I understand what mistakes I made.

Answer 1

A quick check seems to show some errors... let me try and detail the solutions to help you out.

PROBLEM 1:
Diane took 1 1/2 times as long as Amy:
D = 1 1/2 * A
9 = 3/2 A
A = 9 * 2/3
A = 6

Amy took 6 hours

PROBLEM 2:
Let S be salary before deductions
S - 1/4 S = 585
(1 - 1/4) S = 585
3/4 S = 585
S = 585 * (4/3)
S = 195 * 4
S = 780

PROBLEM 3:
J + G = 89
J = 3G + 1

Substituting J into the first equation:
(3G + 1) + G = 89
4G + 1 = 89
4G = 88
G = 22

Then plugging G back into the first equation:
J + G = 89
J + (22) = 89
J = 89 - 22
J = 67

Joan sold 67 (and Gayle sold 22)

Answer 2

1.- answer is 6

diane = ami + ami/2
9 = 3ami/2
ami = 9*2/3 = 6

2.- answer is 780

(same thinking as #1)

payed = original - original/4
585 = 3*original/4
original = 585*4/3
original = 780

3.- system of 2 equations and 2 vars

(A) Johan+Gayle = 89
(B) Joan = 3*Gayle +1

substitute Joan on (A)

3*Gayle+1 + Gayle = 89
4*Gayle = 88
Gayle = 22

Joan = 3*(22) + 1
Joan = 67

67 + 22 = 89

Answer 3

do not imagine so... if Richard is 14, and, in accordance to the problem, 14=2s-4... fixing for s, 18=2s s=9... good? does 9+14=20? continually verify your answer... once you may. (a million) r = 2s - 4 (2) r+s=20 replace the first into the 2d 2s - 4 + s = 20 Combining s temrs 3s-4=20 including 4 to each and every area 3s=24 Multiplying each and every area with the help of a million/3 s=8 Plugging this cost decrease back into the first equation... r = 2s - 4 r = 2(8) - 4 r = 16 - 4 r = 12 verify r+s=12+8=20... tests. you may also use determinants, and "addition," in spite of the indisputable fact that the reply must be a similar.

Answer 4

1.) answer is 6
2.) answer is $780
3.) answer is 67