Answer:

Step-by-step explanation:
In division of powers with the same base, we must subtract the exponent of the denominator from the exponent of the numerator:

Then applying this to the problem:

Eliminating the parentheses:

Answer:
y=.1x+40; Your total monthly bill is $48 for 80 text messages.
Step-by-step explanation:
y is your total bill
x represents each text message
40 is you cellphone bill cost
.1 is the cost per text message
(y=.1x+40 becomes your equation)
plug 80 to represent "x"
y=.1*80+40 ---> y=48
your total monthly bill is $48
Answer:
a) 2L + 2W = 42
b) L = 2W + 3
c) The system is :
2L + 2W = 42
L - 2W = 3
( add the two equations )
3L + (2w - 2w) = 45
3L = 45
L = 45/3
L = 15 ( Length )
L - 2W = 3
15 - 2W = 3
2W = 15 - 3
W = 12/2
W = 6