Answer:
Difference of squares:
y^4−25
16x^2−81
Not difference of squares:
20m^2n^2−121
p^8−q^5
Step-by-step explanation:
y^4−25
(y²)² - 5²
16x^2−81
(4x)² - 9²
20m^2n^2−121
20 is not a perfect square
p^8−q^5
q⁵ is not a perfect square
Answer:
Step-by-step explanation:
(9x-1)^-1/2 - (x+2)(9x-1)^-1/2
= (9x-1)^-1/2( 1 - (x + 2))
= (9x-1)^-1/2(-1 - x)
= -(x + 1)(9x-1)^-1/2
= -(x + 1) / (9x-1)^1/2
Step-by-step explanation:
1st digit is 1 number (1)
2nd digit is (3,4,5) so it's 3 numbers
third digit is (6,7,8,9) is it's 4 numbers
last 7 digits is 10 (0,1,2,3,4,5,6,7,8,9)
multiply
1*3*4*10=120
so answer is 120 phone numbers
Cookies : 9, 18, 27, 36,
Ice cream: 12, 24, 36
So in 36 days.
