Answer:
more than 200 calls
Suppose number of calls = x
According to plan 1: Total monthly charge is $24
According to plan 2: Fix charge is $16 and $0.04 per call
cost of x's call = $0.04x
and monthly charge according to plan 2 = 0.04x + 16
a) Plan 1 is more economical than plan 2.
0.04x + 16 > 24
solve it for x
.04x > 8
x > 200
b) So, if more than 200 calls are made then Plan 1 is more economical.
Step-by-step explanation:
10y less than or equal to 12x
10y <= 12x
1/2 ,2/3,1/3 hear are greater than -5/7
Answer:
8x² + 8
Step-by-step explanation:
Given
(x² + 3)² - (x² - 1)² ← expand both factors using FOIL
= 
+ 6x² + 9 - ( - 2x² + 1) ← distribute by - 1
= + 6x² + 9 - + 2x² - 1 ← collect like terms
= 8x² + 8
