Let us find the slopes of the two lines
ax+by=c, slope m1 = -a/b
bx-ay=c, slope m2 = b/a
m1*m2 = (-a/b)(b/a) = -1
Therefore the two lines are perpendicular so the answer is D
100 m = 10,000 cm thus 10,000 cm - 60 cm = <span>9,940 cm or 9.940 m</span>
Answer:
yea its in the book
Step-by-step explanation:
Answer:
drone is 60km/h bird 40km/h
Step-by-step explanation:
Step-by-step explanation:
Let the two-digit number is 
<u>This can be written as:</u>
- 10x + y, where 1 ≤ x ≤ 9 and 0 ≤ y ≤ 9
<u>The difference between the number and product of its digits is:</u>
<u>Rewrite this as below:</u>
d = 10x - xy + y - 10 + 10 =
x(10 - y) - (10 - y) + 10 =
(x - 1)(10 - y) + 10
<u>We see that:</u>
- 0 ≤ x - 1 ≤ 8 according to the condition given above
- 1 ≤ 10 - y ≤ 10 again according to the condition given above
<u>The value of d is then:</u>
- 0 + 10 ≤ d ≤ 8*10 + 10
- 10 ≤ d ≤ 90
<h3>Proved</h3>