9514 1404 393
Answer:
(1, 1)
Step-by-step explanation:
Did you watch the video?
The y-coefficients have opposite signs and one is a multiple of the other. It is convenient to divide the second equation by 2 and add that to the first.
(5x -2y) +1/2(4x +4y) = (3) +1/2(8)
7x = 7 . . . . simplify
x = 1 . . . . . divide by 7
__
4(1) +4y = 8 . . . . substitute for x in the second equation
4y = 4 . . . . . . . . subtract 4
y = 1 . . . . . . . . . . divide by 4
The solution is (x, y) = (1, 1).
Make a proportion.

⇒

=

Solve for x to find the weight of the elephant on planet B. Cross multiply; (100)(x) and (3)(2200).
You now have:
100x = 6600.
Divide both sides by 100.
x = 66
The elephant would weigh
66 pounds on planet B.
9p + 8 = 10p + 7
- 9p - 9p
8 = p + 7
- 7 - 7
1 = p
Answer:
A. 55 miles/hour
Step-by-step explanation: