These two questions are not connected.

4a. 7 phones on phone plan

4b. 10 phones

Other Problem: a = dy + cd

Step-by-step explanation:

4a.

1. First make equation: y = 15x+50

2. Plug in Number

155 = 15x + 50

-50                 -50

105 = 15x

15        15

x = 7

4b.

1. Make Equation: 200 greater than or equal to 15x + 50

2. Solve

200 greater than or equal to 15x + 50

-50                                                   -50

150 greater than or equal to 15x

15                                             15

x = 10

Second Question

y = a/d - c

Step 1: Move C to other side

y = a/d - c

+c         +C

y+c = a/d

Step 2: Isolate A (Multiply all by d)

(multipy d to y and c) (d) y+c = a/d (d) (multiply by d to isolate a)

a = dy + cd

according to this law, when unemployment goes up by 1%, gdp drops by 2%. in the question, unemployment rate goes from 2% to 5%, meaning unemployment goes up by 3%, so the gdp drops by 6%. thus the effect is a drop in gdp by 6%.

step-by-step explanation: