Answer: x = 1 and y = 2
Given:
y = -3x + 5
5x - 4y = -3
Since we are given y, let’s sub it in the second equation.
5x - 4(-3x + 5) = -3
5x + 12x - 20 = -3
17x = 17
x = 1
After finding x, we can now find y.
5(1) - 4y = -3
-4y = -8
y = 2
Checking:
y = -3x + 5
2 = -3(1) + 5
2 = 2
5x - 4y = -3
5(1) - 4(2) = -3
-3 = -3
Answer:
The tank will empty in 4 hours.
Step-by-step explanation:
Since a barrel contains 56 liters of kerosene, and it has two taps, one tap that draws 500 ml every 6 minutes and after first 5 liters are drawn from the barrel, the second tap also starts, and it draws 1 liter in every 5 minutes, to determine how many hours will be taken in all to empty the tank, the following calculation must be performed:
0.5 x X = 5
X = 5 / 0.5
X = 10
10 x 6 = 60
1 hour = 51 liters
1 hour 30 minutes = 51 - (1 x 6) - (0.5 x 5) = 42.5
2 hours = 42.5 - (1 x 6) - (0.5 x 5) = 34
2 hours 30 minutes = 34 - (1 x 6) - (0.5 x 5) = 25.5
3 hours = 25.5 - (1 x 6) - (0.5 x 5) = 17
3 hours 30 minutes = 17 - (1 x 6) - (0.5 x 5) = 8.5
4 hours = 8.5 - (1 x 6) - (0.5 x 5) = 0
Therefore, the tank will empty in 4 hours.
Answer:
D.) c is multiplied by 4
Step-by-step explanation:
If a is doubled, it becomes 2a. If b is doubled, it becomes 2b. Now we replace a with 2a and b with 2b and simplify.
Answer: D.) c is multiplied by 4
1/2+ 1/4
= 2/4+ 1/4
= 3/4
1/12+ 1/6
= 1/12+ 2/12
= 3/12
= 1/4
Therefore, 1/4+ 1/6+ 1/12
= (1/12+ 1/6)+ (1/12+ 1/6)
= 2*(1/12+ 1/6)
= 2* (1/4)
= 2/4
= 1/2
Hope this helps~
You're trying to find constants
such that
. Equivalently, you're looking for the least-square solution to the following matrix equation.
To solve
, multiply both sides by the transpose of
, which introduces an invertible square matrix on the LHS.
Computing this, you'd find that
which means the first choice is correct.
