Solve algebrically 3x - 4y = -24 and x + 4y = 8 is x = -4 and y = 3
<u>Solution:</u>
We have been given two equations which are as follows:
3x - 4y = -24 ----- eqn 1
x + 4y = 8 -------- eqn 2
We have been asked to solve the equations which means we have to find the value of ‘x’ and ‘y’.
We rearrange eqn 2 as follows:
x + 4y = 8
x = 8 - 4y ------eqn 3
Now we substitute eqn 3 in eqn 1 as follows:
3(8 - 4y) -4y = -24
24 - 12y - 4y = -24
-16y = -48
y = 3
Substitute "y" value in eqn 3. Therefore the value of ‘x’ becomes:
x = 8 - 4(3)
x = 8 - 12 = -4
Hence on solving both the given equations we get the value of x and y as -4 and 3 respectively.
Answer:
Speed of plane in still air: 490 mile/hour
speed of wind: 70 mile/hour
Step-by-step explanation:
still speed = x wind speed = w
with wind: speed = still + wind
(x+w) * 3 = 1680 ...a
against wind: speed = still - wind
(x-w) * 4 = 1680 ...b
b-a ... 4x-4w-3x-3w = 0
x-7w = 0
x = 7w
substitution: (7w+w)*3 = 1680 8w = 560 wind speed (w) = 70
still speed (x) = 7w = 490 mile/hour
Answer:
d
Step-by-step explanation:
if I divide the units of the scaled rectangle by the original you will get
Answer:
F
Step-by-step explanation:
Answer:
Step-by-step explanation:
- Speed in one direction = 40 km/h
- Speed on return = x
- Average speed = 60 km/h
Let the distance be d
<u>Average speed </u>
- 2d/(d/40 + d/x) = 60
- d/40 + d/x = 2d/60
- 1/40 + 1/x = 1/30
- 1/x = 1/30 - 1/40
- 1/x = (4-3)/120
- 1/x = 1/120
- x = 120 km/h
