It works because 7 x 9 x 10 is the same thing as 7 x 90, since 9 x 10 is just 90. So basically he is just writing more but the answer will still be the same.
Answer:
distance formula attached...
it's approximately 8.6
Step-by-step explanation:
Use substitution.
2p + 3(2p) = 680
2p + 6p = 680
8p = 680
p = 85
Plug in.
x = 2p
x = 2(85)
x = 170
p = 85
(9√25) /√50 = 9*5/√50 now simplify the denominator. √50=√25*√2=5√2
so (9*5)/(5√2) simplifies to 9/√2. To rationalize the denominator multiply both the numerator and the denominator by √2.
9√2/(√2*√2) = 9√2/2
Ok so you have 4, x^6 / 2, x^4. Now divide the coefficient so 4/2=2. So 2 x^6/x^4, now subtract the numerator by the denominator so x^6-x^4=x^2 so now you have 2x^2
Answer: 2x^2