Add the exponents if the bases are the same, multiply the bases if the exponents are the same, if nothing is the same just solve it.
If you are buying something that cost $15 and sale tax is 6%, you can calculate final bill trough proportions:
$15:100%=$x:106%
100x=106*15, x=(106*15)/100, x=$15.9 is final bill.
You can also use easier way: $15+0.06*$15=$15.9
Explanation for 2nd way: Cost is $15, on that you need to add 6% of $15: (6%/100%)*$15 and that is 0.06*15.
Answer:
-5 =x
Step-by-step explanation:
3^(x-1) = 9^(x+2)
Replace 9 with 3^2
3^(x-1) = 3^2^(x+2)
We know that a power to a power means the powers are multiplied
a^b^c = a^(b*c)
3^(x-1) = 3^(2x+2)
When the bases are the same, the powers have to be the same
x-1 = 2x+4
Subtract x from each side
x-x-1 =2x-x+4
-1 =x+4
Subtract 4 from each side
-1-4 =x+4-4
-1-4 = x
-5 =x
Answer:
35% discount
Step-by-step explanation:
We can first find what percent of 32 20.80 is.
This can be shown by using a percent proportion.

We can cross multiply to find the value of
.

So 20.80 is 65% of 32.
However, this is the percent of the original price. To find the discount, we have to subtract 65 from 100.

So the book was on a 35% discount.
Hope this helped!
Answer:
(0,-5)
Step-by-step explanation:
3(4x+4y=20)
-3x-12y=-60
12x+12y=60
-3x-12y=-60
9x=0
x=0
4(0)+4y=-20
4y=-20
y=-5