EXPLANATION of SELECT DIFFICULT HW QUESTIONS
Algebra Homework from Thursday Sept 10 ,2015
Pgs 431 and 436
Pg 431 question 48
2n × 2n+2 × 2 =
2n × 2n+2 × 21 =
Rule: When multiplying expressions with the same bases, just add the
exponents. The exponents are:
n + n + 2 +1 =
2n + 3 so the answer becomes:
22n+3
Let's check this using a small #. Let n = 3.
23 × 23+2 × 2 = 8 × 25 × 2 =
Now what about 22n+3
= 2 2(3)+3 = 2 6+3 = 29 = 512
Pg 431 question 52
5 x+1 x 5 1-x
Just add up the exponents so
x+ 1 + 1 – x = 2
So the answer is 52 or 25.
8 x 32 x 2 = 512
Pg 436 question 22
(3n-6)-4
So there were 2 things in question here. 1st, since we are raising a power to
another power, we need to multiply the exponents. If there are negative
exponents, simplify or combine the exponents before you create fractions.
Also, since there is a coefficient inside the parenthesis, this too needs to be
raised to the exponent outside the parenthesis. So now we have
3-4n-6(-4) =
(
1
81
) n24
= n24 / 81
Pg 436 question 24
(5y 1/2)4 Here too, we have a coefficient inside the parenthesis that needs
to be raised to the 4th power.
54y2 = 625y2
Pg 436 question 28
(r 2/5 s)5 So here, we just have to make sure we multiply the 2/5 exponent
by 5.
= r(2/5)5 s5 = r2s5