This is a system of linear equations. We can solve by elimination. First, we write out the two equations:
3m - 4n = 1
4m - 6n = 5
We want to make the coefficients of one of the variables the same so that we can eliminate it. Let's make the coefficient of m 12 for both equations. To do that for the first, we have to multiply both sides by 4:
12m - 16n = 4
To do that for the second, we have to multiply both sides by 3:
12m - 18n = 15
Put the two equations together:
12m - 16n = 4
12m - 18n = 15
We can subtract the bottom equation from the top and eliminate the 12m to get:
-16n - (-18n) = 4 - 15
2n = -11
n = -5.5
Now that we know n, we can solve for m. We can use one of the original equations and put in the value -5.5 for n and solve for m: 3m - 4 * (-5.5) = 1
3m + 22 = 1
m = -7
and
n = -5.5
3m - 4n = 1 Equation 1
4m - 6n = 5 Equation 2
We clear the m variables in the two equations
m = (1+4n)/3 Equation 1
m = (5 +6n)/4 Equation 2
Now we match them
(1+4n)/3 = (5+6n)/4
4(1+4n) = 3(5+6n)
4+16n = 15 +18n
16n - 18n = 15 -4
-2n = 11
n = -11/2
Now we substitute this value in one of the equations
4m -6n = 5 Equation 2
4m -6(-11/2) = 5
4m +66/2 = 5
4m + 33 = 5
m = (5 -33)/4
m = -28/4 = -7
Answer m = -7 and n = -11/2
checking
3*(-7) - 4(-11/2) = 1
-21 +44/2 = 1
-21 +22 = 1 Correct !
4(-7) -6(-11/2) = 5
-28 +66/2 = 5
-28 +33 = 5 Correct!
The angle of elevation must be 68.202 degrees
Solution:
Given that, 14 foot ladder is used to scale a 13 foot wall
We have to find the angle of elevation must the ladder be situated in order to reach the top of the wall
The figure for this solution is attached below
The ladder, wall and the ground forms a right angled triangle
ABC is a right angled triangle
AB is the height of wall = 13 feet
AC is the length of ladder = 14 feet
We have to find the angle of elevation
Let the angle of elevation be "x"
For right angled triangle ABC, We can use the definition for sine
Here, in figure, opposite = AB and hypotenuse = AC
Thus the angle of elevation must be 68.202 degrees
The angle of elevation the ladder will be situated in order to reach the top of the wall is 68°.
A right triangle has one of its angles as 90 degrees. The angle of elevation can be found using trigonometric ratios.
Therefore, the angle of elevation can be calculated as follows;
The length of the ladder is the hypotenuse.
The opposite side is the height of the wall.
Therefore,
sin ∅ = opposite / hypotenuse
sin ∅ = 13 / 14
∅ = sin⁻¹ 0.92857142857
∅ = 68.2129901712
∅ = 68°
learn more on right triangle here: brainly.com/question/22479729
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Answer:
c = 7
Step-by-step explanation:
given 2c = c + 7 ( subtract c from both sides )
c = 7