7(15) = 105
10% off means u r paying for 90%...
0.9(105) = 94.50 <=
Remark
You'll see it a whole lot easier if you make a substitution so that it looks like something you have already seen
Solution
let y = x^2
x^4 = x^2 * x^2
x^4 = y * y
x^4 = y^2
Now the expression becomes
y^2 + 8 y - 9 = z
(y + 9)(y - 1) = z
Now put the x^2 back in.
(x^2 + 9) ( x^2 - 1) = z
x^2 - 1 becomes x + 1 and x - 1. At this level x^2 + 9 can't be factored.
Answer
(x^2 + 9) (x + 1)(x - 1)
Answer is 3/72
multiply the denominator and numerator of 3/8 by 9 (27/72)
multiply the denominator and numerator of 3/9 by 8 (24/72)
this is to get the same denominator of 72
then just subtract
27/72 - 24/72 = 3/72
Answer:
24
Step-by-step explanation:
Since at the retailer you find a choice of 4 CD players, 2 amplifiers and 3 sets of speakers. We have 4 different ways of selecting the CD players, we also have 2 different ways of selecting the amplifiers and 3 different ways of selecting the 3 sets of speakers.
So, the total number of different HiFi systems are available to purchase from this retailer is 4 × 3 × 2 = 24 .
So we have 24 different HiFi systems are available to purchase from this retailer
