Answer:
3. The first equation can be multiplied by 3 and the second equation by 2.
Step-by-step explanation:
2 x + 3 y = 25 (1)
-3 x + 4 y = 22 (2)
Multiply equation (1) by 3 and (2) by 2.
3(2x) = 6x
2(-3x) = -6x
When you add the two equations, x will get cancelled last
Hello!
You first cross multiply
4 * 7 = 28
5 * r = 5 * r
r * 5 = 28
Divide both sides by 5
r = 28/5 = 5.6
The answer is 28/5 or 5.6
Hope this helps!
Answer:
4.2
Step-by-step explanation:
5.7-1.5=4.2
Answer:
Yes because she ends up back at zero
Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
